The Constitutional Dialogue in Europe: A "political" dialogue
Laurence Burgorgue-Larsen 
Cite as Burgorgue-Larsen, L., "The Constitutional Dialogue in Europe: A "political" dialogue", (2015) 21(1) European Journal of Current Legal Issues.
Constitutional Courts have always been closely linked to the Court of Justice. The dialogue - via corresponding rulings - has never ceased to be central to the European integration process, for example to create a catalogue for the protection of fundamental rights or to ensure the longevity of essential principles for EU Law effectiveness such as primacy. However, this dialogue has obviously taken a new turn since various Constitutional Courts have used propio motu, the preliminary reference procedure.
Paterson mainly uses the British example to assess the relevance of dialogue between the (new) British Supreme Court and the Court of Justice of the EU. This explains a lot. It is hard to disagree with his statement in the "British context" and given a fantastic sociological investigation, but one can add nuance. Considering a larger spectrum encompassing the specifics of modern continental constitutionalism suggests that the relationship established between Constitutional Courts and the Court of Justice of the EU thanks to the preliminary reference mechanism is eminently political.
For what reasons do Constitutional Courts engage in direct dialogue with the CJEU? What has encouraged them to activate the preliminary reference mechanism under Article 267(3) TFEU? This article will attempt to answer these questions and examine the follow up to the "integrated" dialogue embodied by this mechanism.
Implementation of the European arrest warrant,  protection of secrecy between lawyers and their clients in the context of the fight against money laundering,  the quality of social services,  protection of personal data , the principle of non-discrimination based on sex  and, last but not least, economic and financial issues : These are issues that were referred for a preliminary ruling in recent years by several Constitutional Courts in accordance with Article 267(3)TFEU. Given such developments, is it possible to state that dialogue between domestic courts and the CJEU is not productive, as Alan Paterson seems to suggest; that it is successive "monologues" rather than genuine dialogue, fuelled mostly by non legal interactions?
Alan Paterson mainly uses the British example to assess the relevance of dialogue between the (new) British Supreme Court and the Court of Justice of the EU.  This explains a lot. It is hard to disagree with his statement in the "British context" and given a fantastic sociological investigation,  but one can add nuance. Considering a larger spectrum encompassing the specifics of modern continental constitutionalism suggests that the relationship established between Constitutional Courts and the Court of Justice of the EU thanks to the preliminary reference mechanism is eminently political.
Constitutional Courts have always been closely linked to the Court of Justice. The dialogue - via corresponding rulings -  has never ceased to be central to the European integration process, for example to create a catalogue for the protection of fundamental rights  or to ensure the longevity of essential principles for EU Law effectiveness such as primacy.  However, this dialogue has obviously taken a new turn since various Constitutional Courts have used propio motu, the preliminary reference procedure.
Since the Constitutional Courts of Austria, Belgium, France, Germany, Italy, Lithuania and Spain have activated Article 267(3) TFEU - and others made clear they may (the Courts of Portugal and Poland) - the constitutional and therefore highly political scale of the dialogue has been established. This is not only in organic terms in that preliminary references are submitted by Constitutional Courts, but also and above all at a substantial level as the issues concerned impact European Constitutional Law as they deal almost exclusively with fundamental rights.
For what reasons do Constitutional Courts engage in direct dialogue with the CJEU? What has encouraged them to activate the preliminary reference mechanism under Article 267(3) TFEU? This article will attempt to answer these questions (Section 2) and examine the follow up to the "integrated" dialogue embodied by this mechanism. The only way to evaluate, as close to reality as possible, the positive or negative force of the dialogue is to analyse how Constitutional Courts take the Court of Justice's answers into account (Section 3).
2. The reasons for "constitutional dialogue"
There are multiple reasons as to why Constitutional Courts' have entered the dialogue era: It can be a sign of power (2.1) or the consequences of some technical factors (2.2). These reasons can also be intertwined (2.3).
2.1. A sign of power
The first reason is of a general nature. It has to do with the times we live in, marked by globalisation and ever-fading State sovereignty. In this context, it becomes imperative for each player of the European judicial system to "take the floor", making itself heard in order to remind others of its existence and therefore authority.  One must adapt to the new judicial relations if one does not want to decline. As a result, a number of Courts have abandoned their jurisprudence resisting the preliminary reference.
The Spanish case epitomises this state of affairs.  For a long time the Spanish Constitutional Court considered disputes involving questions of interpretation or validity of EU Law were not constitutional.  Therefore, ordinary judges could only, and in some cases should only, activate the preliminary reference procedure. If they did not respect their referral obligation under Article 267(3) TFEU, they were exposed to an amparo ruling establishing a violation of effective judicial protection provided for in Article 24 of the Spanish Constitution.  On 9 June 2011, the Spanish Constitutional Tribunal put an end to that jurisprudence and entered the then closed club of Constitutional Courts that decided to get directly in touch with the Court of Justice.  The Court did not hesitate, in relation to a very sensitive issue (i.e. implementation of the European arrest warrant) to refer three questions to the Court for a preliminary ruling on the interpretation and validity of EU Law. This jurisprudence overturn animated politico-doctrinal debates in Spain  and in Europe and forced the Court of Justice to live up to expectations raised by a referral dealing with complex issues linked to the Charter of Fundamental Rights (Article 53). With this referral to the Court of Justice, the Spanish Constitutional Court became more prominent at the European level and made itself seen and heard: its question was dissected and analysed of academics as well as European judicial stakeholders. By entering the then rather closed club of Constitutional Courts that embodied judicial exchange with the Union, the Constitutional Court "strengthened its institutional legitimacy" according to one of the referral drafters.  Far from being a sign of weakness, the referral characterised power. Moreover, it shows that the Court decided to give up the sterile debate on "judicial hierarchy".
To purposefully engage in dialogue is to make concrete or even strengthen the judicial power of the guarantor of the Constitution. The question was basically whether the protection of fundamental rights should prevail over the unity of implementation of EU Law. The CJEU answer is well known: It took the form of one of the most important rulings of the last few years: In the Melloni judgment the Court of Justice plainly gives priority to implementing EU secondary law.  In other words, the Constitutional Court managed to find the right opportunity to make the Court of Justice face its responsibilities. With every landmark preliminary reference comes a landmark ruling.
Refusing dialogue also asserts some power and judicial authority. Silence can also be revealing, for example with regard to the European bank (the Court of Justice of the EU) and the domestic bank (the Constitutional Courts). When the CJEU took a certain position in the Åkerberg Fransson case  dealing with the scope of the Charter of Fundamental Rights on 26 February 2013  and, in return, the Constitutional Court of Germany only two months later, on 24 April 2013,  gave an opposing interpretation and explained why it would not activate the preliminary reference procedure, this gives us a powerful example of "constitutional dialogue". The Constitutional complaint put before the Karlsruhe-based Court was filed under 2006 legislation that had set up a database to fight terrorism. The legislation allowed for data to be gathered from the federal police, Länder police services and intelligence services. The law came into force in 2007 and led to collecting information from 18,000 people. The German Constitutional Court first had to decide whether to activate the preliminary reference mechanism to allow the CJEU to assess the domestic law's compatibility with the rights and principles enshrined in the EU Charter of Fundamental Rights.  This was not deemed necessary (para. 90). To reach this conclusion, the judges looked into the scope of the German law. They decided that even though some contact points existed with the Law of the EU, neither the referred law nor the actions taken to put it into practice "implemented the Law of the EU" according to Article 51(1)(first sentence). Therefore, the Law of the EU did not need to be clarified and it was not necessary to refer it to the Court of Justice for a preliminary ruling as it was not, in this particular case, the "legal" judge under Article 100(1) of the Constitution. In paragraph 91, the Constitutional Court shares its vision of Article 51(1) of the EU Charter, which clearly opposed the EU Court of Justice's vision in the Åkerberg Fransson case at point 19. The "scope" notion as understood by the Kirchberg Court did not satisfy Karlsruhe judges who found it too invasive. Hence the Constitutional Court decided to "regain control" and deliver a more restrictive interpretation of Article 51(1) than that of the Court of Justice two months earlier. If try and put these kinds of conflicts in context, we realise that what is at stake is nothing more and nothing less than the potential decline of the remit of Constitutional Courts, i.e. their function of predilection (the concrete protection of fundamental rights). A broad conception of "implementation of the Law of the EU" (which is a condition for the applicability of the Charter) mechanically diminishes the possibility of activating the competency of Constitutional judges in terms of protecting fundamental rights. Obviously, this generates new disagreements.  How will the Court of Justice react to this strategic position taken by the German Constitutional Court which unanimously considered that the Åkerberg Fransson ruling set a solution that was limited to the criminal procedure and meaning of the ne bis in idem principle?
2.2. Technical factors
The second factor is more specific as it relates to technical considerations. In other words, it stems from procedural particularities in every Member State's constitutional justice system. Constitutional changes in each country explain why in Belgium,  France  or Italy,  the configuration of new competencies for Constitutional Courts allowed preliminary references. It should be underlined that the Belgian Constitutional Court has become the "preliminary procedure champion" and the relationship hence established with the CJEU is one of the most structured and regular. 
Let us look at France. The decision by the Conseil constitutionnel - an uncommon area of continental constitutionalism - to refer the Jérémy F. case  to the Court of Justice for a preliminary ruling on 4 April 2013 was a "little revolution" in France. As in Spain, it spawned intense doctrinal debate. It was a major change in the French constitutional procedural landscape that led to a change of course in 2013.
For a long time, the vast majority of legal doctrine gave technical reasons for the "non preliminary reference" related to the constitutionality review which takes place a priori in France. Everyone appeared to agree that the preliminary reference procedure before the Constitutional Council that judges the conformity of the law to the Constitution - was impossible as "referral" to the Court did not belong to the "referrers", no "party" was brought before the constitutional judges, there was no "complaint", no motivation was necessary, there was no interest in taking legal action and no conclusions…  How was it possible then to stay the proceedings in order to refer a question about interpretation or validity of the Law of the EU for a preliminary ruling? The preliminary reference procedure was clearly inconceivable with regard to a constitutionality review taking place a priori. The technical argument appeared well-founded. Arguably, it still is… but a dramatic change occurred with the Constitutional reform of 2008 and the subsequent setting up of the famous "QPC" for "Question prioritaire de Constitutionnalité" (priority question of constitutionality). A reviewa posteriori appeared in France.  Thanks to this new procedural setting, everything became possible. However, whilst the referral of the Jérémy F. case - which received broad media coverage and dealt with rules for implementing the European arrest warrant -  was possible through the QPC procedure, it seems that French constitutional architecture will continue to prevent the preliminary reference procedure from becoming widespread. The Conseil constitutionnel felt that it should, or had to, trigger the preliminary reference procedure because of the wording of Article 88(2) of the French Constitution (as provided for by the Constitutional Law of 25 March 2003). According to this provision, " [s]tatutes shall determine the rules relating to the European arrest warrant pursuant to acts adopted by the institutions on the European Union." The Conseil constitutionnel considered that it could not rule on the Court of Cassation's QPC without first referring to the Court of Justice an interpretation issue about the Framework Decision. In doing so, it set responsibilities: the constitutional review for the Conseil constitutionnel and interpretation of the EU Law for the Court of Justice. Incidentally, during a seminar held at the Conseil constitutionnel - an example of dialogue with academia as A. Paterson mentions in his book - Nicole Belloubet, the only member of today's Constitutional Council to be a Professor of Public Law, suggested that this interpretation was correct.
2.3 Accumulation of reasons: between power and technique
Some cases suggest it is a mixture of power and technical reasons that make a Constitutional Court "take the plunge" and formally establish a dialogue with the Court of Justice. In Italy, those two reasons came successively. The first preliminary reference was made for technical reasons; the second one revealed the will "to be heard" and contribute to the "constitutional dialogue" in Europe.
For a long time, the jurisprudence of the Italian Constitutional Court suggested it did not consider itself "a Member State jurisdiction" that could trigger the preliminary reference mechanism provided by Article 267(3) TFEU (former Article 234 EC).  The argument was simple: The Court considered it was not a court "like the others" i.e. ordinary courts that applied Community as well as domestic law.
The change took the form of two rulings of 12 February 2008 (n°102 and 103).  The matter brought before the Court of Justice, on the basis of Article 134 of the Constitution was Sardinian regional legislation that provided for the taxation of some stopovers by aircraft or recreational craft. The tax was only imposed on persons whose tax domicile was outside the region. The State claimed that the regional tax legislation violated the freedom to provide services and the law of State aid. Contrary to a well-established jurisprudence, the Constitutional Court considered itself "a Court of a Member State" which could and did activate in casu the preliminary reference procedure and give its interpretation of EU Law.  The reason for this overturn lies in the particular configuration of the dispute. Under the new Article 117(1) of the Italian Constitution - as a result of the constitutional reform of 2001 - the Constitutional Court is competent to deal with disputes opposing the State to a region or to one of the two autonomous provinces of Trento and Bolzano.  In other words, such disputes are not brought before ordinary judges via a constitutionality question. In this case, the Constitutional Court acts as first and last authority and must abide by Article 117(1) which constitutionalises obligations derived from the Law of the EU. 
The Italian constitutional make-up does not explain the second preliminary reference of 18 July 2013, activated by a constitutionality question.  The procedural context was totally different in 2008. The new case is innovative in many ways. The Constitutional Court seems to be implying that, apart from the very specific cases where it acts as first and last instance in vertical disputes (State vs. regions), it is willing to fully play the "integrated dialogue" game with the Court of Justice.
Until now, it was the doppia pregiudizialità (double preliminary reference) system that ruled the triangular relationships between ordinary judges, the Constitutional Court and the Court of Justice.  When ordinary judges had to deal with a case where the constitutionality of domestic legislation depended on the interpretation of the Law of the EU, they had to refer it to the Court of Justice (following the Simmenthal case philosophy). Such cases were brought before the Constitutional Court only once the Court of Justice had rendered its ruling. These long and complex proceedings attracted much criticism. Therefore, the change implied by the order of 18 July 2013 - about a case on the Italian legislation on rights and obligations of school personnel -  was particularly important. Sadly, what strikes the reader is the absence of any clear understanding of preliminary reference in relation to this change. The Court effectively reduced the significance of the preliminary reference. It stated it had not only already resorted to the procedure when the case was brought before it but it is also one of the "courts" that can trigger the mechanism in the framework of a constitutionality question. There are two possible reasons for such an attitude.  The first one is general and systemic. The Court has taken note of the new relationship between European and national courts, notably due to the strengthening of material interaction. This has partly been driven by the adoption and subsequent entry into force of the Charter of Fundamental Rights. As mentioned in the first part of this article, a court can adhere to constitutional dialogue to make its voice heard and be amongst judicial stakeholders that "count". The second reason is more technical and pragmatic: it is about preventing the Italian State's responsibility from coming into play because it refuses to refer a case to the European Court. This would reveal the effects of the Köbler case law.  These two types of explanation can easily be combined. In any case, if Italy takes the path of a minimum complexity application of the preliminary reference procedure, it will be following its Belgian counterpart … the leader in such matters.
3. The follow-up to constitutional dialogue
Once Constitutional Courts have referred one or several questions to the Court of Justice and it has rendered its preliminary ruling, how do the guardians of the Constitution follow up on the answer from the judges of the Kirchberg Plateau? It is an important question: It reveals whether or not constitutional judges intend to enter era of dialogue in a constructive manner, intend to best apply or not European Law as "judges loyal to the Union" without renouncing their constitutional role. Will their primary concern be to preserve States interests by making the best use of the opportunities deriving from the Court's ruling or will they openly choose a pro integrationae approach? This is important to decipher but not easy to do as it requires immersion in the peculiarities of every legal system. However, when one is brave enough to do this, it shows the jurisdictional reality and all aspects of the dialogue.
The Belgian example is the obvious one. Their Constitutional Court is undoubtedly a leader.  As of 9 February 2015, it had referred 26 cases to the Court of Justice for a preliminary ruling.  Dialogue is calm, durable, open and shows that an intertwining of systems has become commonplace - the last word does not belong to one court alone but in way to all. Four examples will be analysed to demonstrate that the "narrow" canal of the preliminary reference procedure actually has great virtues.
Following judgments in various cases, ASBL  (discrimination based on sex in relation to insurance premiums and benefits), Bressol and Chaverot  (access to university education in the medical and paramedical area), Base NV and Others  (universal service relating to electronic communications and services) and I.B.  (European arrest warrant), the Constitutional Court implemented answers provided by the Court of Justice in its preliminary reference rulings dealing with the interpretation of EU Law (Base NV and Others, Bressol and Chaverot, I.B.) as well as the assessment of its validity ( ASBL). The Belgian Constitutional Court's dialogical empathy is striking: It is an unambiguous "loyal judge to the Law of the EU" whilst still being a brilliant and subtle Constitutional judge. In each case, it resorts to an interpretation of secondary law that complies with the Constitution. Therefore, its dual loyalty (towards the Constitution and EU Law) is not a problem. There is no "duel" between allegiances. In short, the Belgian Constitutional Court is undoubtedly an excellent "partner"  of the Court of Justice.
In the case dated 27 January 2011,  the Constitutional Court exceptionally aligned with the CJEU preliminary ruling (CJEU, 6 October 2010, SA Base, C-389/08) on the reference of 8 September 2008 about interpretation of Article 12 of the Universal Service Directive of 7 March 2002 (Directive 2002/22/EC). The case was interesting since the CJEU delivered on the very same day (6 October 2010) a judgment establishing Belgium's failure to fulfil its obligations (case No C-222/08) to implement the Universal Service Directive correctly. For that reason, it would have been surprising, had the Constitutional Court ignored the preliminary ruling as well as the judgment on failure as both coincide on the substance. As a consequence, its decision was very clear:
"Following on the motivation of the aforementioned rulings by the Court of Justice, the legislature, by treating all operators in the same way, as stated by the Council of Ministers in its briefs and the supplementary brief submitted after the Court of Justice's judgments, and as resulting from the travaux préparatoires (Doc. parl., Chambre, 2006-2007, DOC 51-2873/011, p. 3), by regarding any net costs resulting from the obligation to apply social tariffs as representing, for the undertakings concerned, an unfair burden which must necessarily give rise to compensation, without carrying out a specific assessment of the net cost which the provision of universal service represents for each operator concerned, failed to fulfil its obligations under Article 13 of the Universal Service Directive. In as much as the legislature treats all operators in the same way, whereas Articles 12 and 13 of the Universal Service Directive provides for a differentiated treatment of operators in concreto, it has also violated the principle of equality and non discrimination guaranteed by Articles 10 and 11 of the Constitution. Under this principle, categories of persons who find themselves in a different situation with regard to the concerned measure must not be treated in the same way unless there is a reasonable justification for doing so." (Point B. 10, unofficial translation)
To breach the Law of the EU is to breach the Constitution. The equation can only function if Constitutional Law is analysed and interpreted in the light of European standards.
In the case of 24 February 2011,  the Belgian Constitutional Court once again follows the interpretation given by the Court of Justice (CJEU, 21 October 2010, I.B., C-306/09) relating to European arrest warrant implementation.  The Constitutional Court - to which the matter had been referred by the judge a quo (the court from which the cause had been removed) - asked whether Member States could make surrender to the judicial authorities of the issuing State of a person residing on their territory who is the subject of an arrest warrant for the purposes of the execution of a sentence imposed in absentia, subject to a condition that that person be returned to the executing State in order to serve there the custodial sentence or detention order imposed by a final judgment against that person in the issuing State. In its I.B. ruling, the Court of Justice held that it was possible for a Member State to subject the execution of an arrest warrant to such condition. According to the CJEU, by providing that execution of the European arrest warrant may be refused if "the requested person is staying in, or is a national or a resident of the executing Member State" or "if a person who is the subject of a European arrest warrant (…) is a national or resident of the executing Member State", Article 4(6) and 5(3) of the Framework Decision have "the objective of enabling particular weight to be given to the possibility of increasing the requested person's chances of reintegrating into society" (I.B., C-306/09, at point 52). In this context, the Belgian Constitutional Court gave a pro integrationae interpretation of the Belgian Law of 2003 transposing the Framework Decision on the European arrest warrant. Interestingly, it did so by presenting two possible interpretations: one contrary to the Constitution (and therefore contrary to the Law of the EU); the other in line with the Constitution (and thus with the Law of the EU).  According to this approach, it will be very difficult for the court a quo to discard the interpretation which is in line with both the Constitution and the Law of the EU…
In its Bressol and Chaverot judgment issued on 31st May 2011,  the Belgian Constitutional Court only partly invalidated the decree adopted by the French Community of Belgium on 16 June 2006 which governs the number of students not considered as resident in Belgium who may enrol in its institutions of higher education for some medical and paramedical courses. The limited number of students not considered as resident in Belgium was thus maintained. It was not a defiant stance towards the answer given by the Court of Justice. On the contrary, the Constitutional Court subtly used the derogation stated by the CJEU. In its judgment of 13 April 2010, it had itself ruled that a difference in treatment, as established by the French Community decree, based indirectly on nationality, may be justified to fulfil the objective of maintaining a balanced, high quality medical service open to all, in so far as it contributes to achieving a high level of protection of health. The CJEU considers it is for the referring court to establish that there are genuine risks to the protection of public health. Applying the different criteria stated by the Court of Justice, the Constitutional Court, based on figures provided by the French Community Government, assessed for each curriculum whether the restrictive legislation could be regarded as appropriate and proportionate for attaining this goal. Regarding the curricula of physiotherapy and veterinary medicine, the Constitutional Court based its judgment on several studies and lists of professions affected by skill shortages. The Court first observed a shortage of physiotherapists in the French Community as well as an excessive number of students of veterinary medicine, thus revealing a risk for public health. The Court then verified that the limited number of students considered as non resident has effectively allowed - and would allow in the future - the number of physiotherapists to rise and to improve the quality of education provided to veterinary physicians. Finally, assessing whether the restrictive legislation was proportionate, the Constitution Court held that firstly, it allowed for a wide access to the concerned education (on average 10% students considered non resident) and secondly, the system of drawing lots aimed to pick non resident students was not controversial (contrary to a selection system based on application or by order of registration). However, the Court invalidated the decree with regard to other curricula (midwives, ergotherapy, etc.) because of insufficiently precise figures showing a diminishing quality of education for these curricula. Therefore, it is on the basis of an extremely detailed analysis respectful of the CJEU that the Constitutional Court put an end to a very sensitive political case that received wide media coverage in Belgium and France…
In its ruling of 30 June 2011 - issued soon after the Court of Justice invalidated Article 5(2) of Directive 2004/113 in its ASBL judgment of 1st March 2011 - the Constitutional Court aligned with the CJEU's case law. It even went further than invaliditing a sole provision. The Court considered that "review is stricter where the fundamental principle of gender equality is at issue" (at B.11 in fine) and did not hesitate to repeal the entire law that meticulously transposed Directive 2004/113,  whilst also aligning with the temporal flexibility provided by the Court of Luxembourg. Showing concern for coherence (with the CJEU) and (legal) pragmatism, it ruled that:
"Like the Court of Justice, the Court considers the provision of a transitional period appropriate. On the one hand, it will allow insurance companies to adapt to the new conditions deriving from the present ruling and the ruling of the Court of Justice issued on 1st March 2011 and to modify their products accordingly; on the other hand, it should be taken into account that to retroactively repeal the concerned law, and in particular its Article 3, would in effect resuscitate the former Article 10 of the aforementioned law of 10 May 2007, of which paragraph 3 limited the validity of the authorised derogation by the first paragraph of the said Article 10 to the 21 December 2007. The decision to give the legislature the faculty and time to intervene again allows it to determine whether distinctions based on sex in relation to insurance premium and benefits as of the date at which the prohibition will take effect also applies or not to contracts concluded before the said date - an issue on which the parties diverge. B. 16.2. The effects of the repealed legislative provisions are thus retained until 21st December 2012 the latest." (Unofficial translation)
Such examples demonstrate that dialogue between the highest courts (in this instance the Belgian Court) and the Court of the Union can be very productive and result in full agreement.
The field of legal studies on the new dialogical relations between the Court of Justice and Constitutional Courts deserves to be further explored. Whilst dialogue through the preliminary reference seems to be in order, all methodological tools will be necessary - notably comparative law - in order to be able to decipher it without missing its meaning or its implications for European integration.
This brief exercise shows that, aside from the sociological expressions of the dialogue emphasised by A. Paterson in his book, a focus on strictly legal interactions may also be very revealing, especially when they are between the guardians of the Constitutions and the Court of Justice of the Union.
 Laurence.Burgorgue-Larsen@univ-paris1.fr, Research Institute for International and European Law at Sorbonne Law School. President of the Constitutional Tribunal of Andorra.
 Belgian Court of Arbitration, question of 29 July 2005; ECJ judgment, Grand Chamber, 3 May 2007, Advocaten voor de Wereld VZW, C-303/05; Belgian Constitutional Court, 31 July 2009; CJEU judgment of 31st October 2010, I.B.; Spanish Constitutional Court, 9 June 2011, No ATC 86/2011; CJEU judgment, Grand Chamber, 26 February 2013, Melloni, C-399/11; French Constitutional Council, Jeremy F. , 4 April 2013, DC No 2013-314P QPC; CJEU judgment, 30 May 2013, Jeremy F. v. Premier ministre, C-168/13 PPU.
 Belgian Court of Arbitration, question of 13 July 2005; ECJ judgment, Grand Chamber, 26 June 2007, Ordre des barreaux francophones et germanophone, C-305/05.
 Belgian Constitutional Court, 25 January 2012 N° 10/212 ( Etablissements personnes âgées (Fédération des maisons de repos privées de Belgique (Femarbel) ASBL / Commission communautaire commune).
 Belgian Constitutional Court, 10 October 2012, N° 116/2012, so-called "private detectives" case (Institut professionnel des agents immobiliers (IPI)/Geoffrey Englebert, Immo 9 SPRL, Grégory Francotte).
 Belgian Constitutional Court, question of 29 June 2009; CJEU 1st March 2011, ASBL.
 Federal Constitutional Court of Germany, 14 January 2014, 2 BvR 2728/13, 2 BvR 2729/13, 2, BvR 2730/13, 2 BvR 2731/13, 2 BvE 13/13.
 A. Paterson, Final Judgment : the last law lords and the Supreme Court, Cambridge, University Press, 2013, 322 p.
 His book is fascinating for a "continental" legal expert like myself. Not only is it an impressive legal study, it is also an incredible sociological investigation into the ways of thinking that lead to judicial decisions. There are many interviews and "tasty" stories. This "genre" is quite rare in French legal literature. There are only two major exceptions that can be explained because of their authors' background. When Dominique Schapper, academic and Professor of sociology, left the Conseil constitutionnel, she offered readers a gem entitled Une sociologue au Conseil constitutionnel, Paris, Gallimard, 2010, 464 p. The second example comes from Bruno Latour, philosopher, anthropologist and sociologist who, after an investigation in situ at the Conseil d'Etat, delivers a highly unusual work in French legal studies on law-making at the Palais Royal. La fabrication du droit. Une ethnographie du Conseil d'Etat, Paris, La découverte, 2004, 320 p.
 I refer to a narrower concept than the one developed by A. Paterson who also takes into account the "judicial diplomacy" including e.g. informal relations between judges. For my part, when answering what "dialogue between judges" means, I think we can agree that it is for two or more courts to express - through a judicial ruling - an agreement or disagreement on a particular issue. Dialogue is not necessary agreement; it can express disagreement. This is a fundamental as it lays the foundations of the dialogical approach. When analysed in the very particular context of European integration, the dialogue between courts reveals processes that are constantly developing: As long as integration holds, so does the dialogue; when integration evolves, the dialogue does too. I had an opportunity to develop this approach when paying tribute to a great legal expert of the Conseil d'Etat, "L'internationalisation du dialogue des juges", Mélanges en l'honneur de B. Genevois, Paris, Dalloz, 2009, pp. 95-130.
 The vertical dialogue that lasted for years and still reappears regularly between the Court of Justice of the EU and the Constitutional Courts - and basically led to the counter-limits theory - is a "classic" of European construction. The Italian Constitutional Court set the tone in its famous San Michele case of 27 December 1965. Since then, thanks to the judicial saga of vertical interaction - that led to unbridled dialogue (i.e. free from any pre-established procedural constraint) - a solid basis was laid in terms of fundamental rights within the EU as well as boundaries to the exercise of transferred competencies. The story is well known: it led to the drafting and the entry into force of the EU Charter of Fundamental Rights.
 One of the main aspects of the Simmenthal ruling is well known: whenever domestic judges have the option to refer constitutional or conventional provisions for a preliminary ruling, the latter prevails. Therefore Mass was said in 1978. Nevertheless, the European landscape is full of contrasts. Constitutional Courts take decisions that are sometimes clearly influenced by the Court of Justice of the EU (Constitutional Court of the Czech Republic) and at other times reveal defiance towards it (Constitutional Court of Germany).
 See the very stimulating doctoral thesis by Daniel Sarmiento who covers the whole case law related to referrals for a preliminary ruling in the light of the "Habermassian" concepts of "communicative action", Poder judicial e integración europea. La Construcción de un modelo jurisdiccional para la Unión, Madrid, Thomson/Civitas, 2004, 379 p. Prólogo de Dámaso Ruiz-Járabo.
 L. Arroyo Jimenez, "Sobre la primera cuestión prejudicial por el Tribunal Constitucional. Bases, contenido y consecuencias", Papeles de Derecho europeo e Integración regional/Working Papers on European Law and Regional Integration, WP IDEIR No 8 (2011), p. 18. See also our analysis in RTDE, 2012, January-March 2012, No 1, pp.271-275.
 Spanish Constitutional Court, STC No 28/1991 of 14 February 1991, FJ No 7 ; STC No 372/1993 of 13 December 1993 ; STC No 265/1994 of 3 October 1994.
 R. Alonso Garcia " Cuestión prejudicial europea y tutela judicial efectiva (a propósito de las SSTC 58/2004, 194/2006 y 78/2010 ", WP IDEIR No 4 (2011).
 In this case, implementation of the European arrest warrant focuses on the particular situation whereby the concerned person did not want to attend her trial (trial in absentia). The Spanish Constitutional case law is very strict: even though the defendant refused to attend his trial and was duly represented, it amounts to a breach of the right to a fair trial.
 I was lucky enough to participate in a congress in Spain a few days after the preliminary reference of 9 June 2011. Intellectual effervescence was at its highest in academia and the judiciary. "It" was all that was talked about, as if the Constitutional Court was very proud to have finally taken the plunge regarding such a sensitive case. "Informal dialogue" was also at its height as the congress gathered the Spanish judge to the CJEU, one of his legal secretaries and legal assistants who had contributed to drafting the preliminary reference.
 L. Arroyo Jiménez, "Sobre la primera cuestion prejudicila por el Tribunal Constitucional. Bases, contenido y consecuencias", Papeles de Derecho europeo e Integracin regional / Working Papers on European Law and Regional Integration, WP IDEIR No 8 (2011), p.18.
 CJEU, Grand Chamber, 26 February 2013, Melloni, case C-399/11 ; See E. Dubout, "Le niveau de protection des droits fondamentaux dans l'Union européenne : Unitarisme constitutif versus pluralisme constitutionnel. Réflexions autour de l'arrêt Melloni", Cahiers de droit européen, 2013, No 2, p. 296.
 CJEU, Grand Chamber, 26 January 2013, Åkerberg Fransson, C-617/10.
 E. Hancox, "The meaning of 'implementing' EU law under Article 51(1) of the Charter: Åkerberg Fransson", Common Market Law Review 2013, No 50, p. 1411. It should be recalled that the CJEU assimilates "implementation" of EU Law (Article 5(1)) and "scope" which, by definition, substantially expands the Court of Justice's scope for intervention.
 Federal Constitutional Court of Germany, 24 April 2013, BVerfG 1 BvR 1215/07.
 The merits of the case are not key to our analysis. It should simply be recalled that the Constitutional Court considered that the database complied, on principle, with the German Constitution as it served a legitimate goal (the fight against terrorism). However, its detailed functioning did not. The modalities for the collection and use of data had, to comply with the proportionality principle, to be set by clear rules, have sufficient limits and be subject to appropriate control. The Constitutional Court considered that these requirements were not met. The provisions allowing for the collection of data regarding persons in contact with terrorists, without knowing their activities, were neither proportionate nor sufficiently precise.
 JHR, LB, "After Akerberg Fransson and Melloni", European Constitutional Law Review, Vol. 9, September 2013, pp. 169-175.
 T. Vandamme, "Prochain arrêt : la Belgique ! Explaining Recent Preliminary Reference of the Belgian Constitutional Court", EuConst., 4, 2008, pp. 127-148.
 Constitutional Council, Jeremy F., 4 April 2013, DC No 2013-314P QPC. See also the Constitutional Council's website for the many doctrinal commentaries (http://www.conseil-constitutionnel.fr/)
 See infra.
 See infra, II. Follow-up to the constitutional dialogue.
 Constitutional Council, Jeremy F., 4 April 2013, DC No 2013-314P QPC.
 J-P Camby, Revue du droit public en France et à l'étranger, 1997-1, pp. 6-12.
 The Organic Law No 2009-1523 of 10 December 2009 (Official Journal of 11 December 2009) implemented the new Article 61(1) of the Constitution. It should be noted that the legislator (in the 2009 Organic Law) and later the Constitutional Council itself, when drafting the rules of procedures relating to the QPC, took into account the treaty requirements in terms of fairness, publicity and impartiality of the procedure. The Secretary General of the Council (M. Guillaume), took up his pen several times to highlight this adjustment. From the point of view of organisational sociology and building upon A. Paterson's work, it is interesting to see that more and more active members of the Constitutional Council (holding various positions) adopt, in their writings, a strategy of communication with academia. See , e.g., M. Guillaume, "Le règlement intérieur sur la procédure suivie devant le Conseil constitutionnel pour les questions prioritaires de constitutionnalité", Les petites affiches, No 38 and Gazette du Palais No 54 of 23 February 2010 ; M. Guillaume, "Question prioritaire de constitutionnalité et convention européenne des droits de l'homme", La conscience des droits. Mélanges en l'honneur de Jean-Paul Costa, Paris, Dalloz, 2011, pp.293-309. Before him, a member of the Constitutional Council had emphasised influence "games" between the Council and the European Court of Human Rights, O. Dutheillet de Lamothe, "L'influence de la Cour européenne des droits de l'homme sur le Conseil constitutionnel", intervention of 13 February 2009 (available on the Constitutional Council's website). See also, by the same author, "Conseil constitutionnel et Cour européenne des droits de l'homme : un dialogue sans paroles", Le dialogue des juges. Mélanges en l'honneur du président Bruno Genevois, Paris, Dalloz, 2009, pp.403-417.
 The case received wide media coverage. An English teacher who had come to France with one of his pupils over fifteen years of age, was arrested on the basis of a European Arrest Warrant issued by the Crown court in Maidstone in the United Kingdom. He was handed over to the British authorities in accordance with a ruling by the Bordeaux investigation chamber (Chambre d'instruction) of 4 October 2012. However, whilst the arrest warrant had been issued for child abduction, the teacher was, upon arrival on British soil, interrogated for sexual activity with a female minor (considered as child sexual abuse which is punished under UK Law until the child is 16 years of age and not 15 in France). Since the British judge, applying the speciality rule, had refused to order the detention on the basis of facts that were not mentioned in the arrest warrant, the British authorities asked their French counterparts to extend the European arrest warrant to cover other offences. The investigation chamber in Bordeaux agreed to extend the arrest warrant on 15 January 2013. However, under Article 695-46 of the French Code of Criminal Procedure, this decision is not subject to appeal. The breach to the right to an effective judicial remedy seems obvious. At issue is a question which greatly affects the applicant since he became liable for offences for which the prison sentence could be twice as long. This provision is the result of the Framework Decision 2002/584/JHA Articles 27 and 28 being transposed into French Law. The decision to extend an arrest issued for any offence committed by the person prior to his or her surrender, or the decision to surrender the person to a Member State other than the executing Member State "shall be taken no later than 30 days after receipt of the request".
 Italian Constitutional Court, Order of 15 December 1995, No 536/1995, copied in Il Foro Italiano 1996, I, p. 783.
 Italian Constitutional Court, 12 February 2008, No 102/2008 and No 103/2008, see the commentary by L. S. Rossi on rulings No 348 and 349/2007 of 22 October 2007 and No 102 and 103 of 12 February 2008, Common Market Law Review, vol. No 46-No 1, 2009, pp.319-331.
 By an order of 12 February 2008 (No 103/2008), the Constitutional Court decided to stay the proceedings of "constitutional legality" to refer 4 preliminary questions to the Court of Justice. Case No is C-169/08,Presidente de Consiglio dei Ministri c. Regione autonoma delle Sardegna. Advocate General J. Kokott presented her opinion on 2 nd July 2009 and underlined that "The present reference for a preliminary ruling marks a turning point in the case law of the Italian Constitutional Court, which has hitherto held that it is not of the nature of a court within the meaning of Article 234 EC. Thus it has now joined the national constitutional courts which have a relationship of active cooperation with the Court of Justice."
 Reciprocally, it can rule principally on actions taken by a region or a province with a special status against a law adopted by another region or by the State.
 Article 117(1) of the Italian Constitution reads: "Legislative powers shall be vested in the State and the Regions in compliance with the Constitution and with the constraints deriving from EU-legislation and international obligations."
 Italian Constitutional Court, Order of 18 July 2013, No 207. L. D'Ambrosio, "La Cour constitutionnelle italienne saisit pour la première fois la CJUE dans le cadre d'une question de constitutionnalité", in Jurisprudences nationales intéressant le droit de l'Union, E. Saulnier-Cassia (ed.), Revue Trimestrielle de Droit européen, January-March 2014, pp. 241-244.
 L. D'Ambrosio, op.cit., p. 242.
 At the heart of the preliminary reference was the question of its compatibility with Directive 1999/70/EC.
 L. D'Ambrosio, op.cit., p. 243.
 CJEU, 20 September 2003, Köbler, case No C-224/01.
 On subtleties and particularities of Belgian Constitutional Law with regard to the Law of the EU, see two studies by M. Verdussen, "La Cour constitutionnelle, partenaire de la Cour de justice de l'Union européenne", Revue belge de droit constitutionnel, 2011, pp. 81-109 and "Le droit de l'Union européenne jouit-il en Belgique d'une singularité constitutionnelle par rapport au droit international ?", Les interactions normatives. Droit de l'Union européenne et droit international, L. Burgorgue-Larsen, E. Dubout, A. Maîtrot de la Motte, S. Touzé (eds.), Paris, Pedone, 2012, pp. 87-105 (Foreword by Alain Pellet ; Col. Cahiers européens, No 2).
 I had several conversations with the two presidents of the Belgian Constitutional Court (A. Alen and J. Spreutels). They revealed how proud and happy they were about the established relationship with the CJEU. The Belgian Court's website reflects the integration of the preliminary reference within its constitutional activities as a specific "tab" was created to allow easy access to preliminary references, CJEU rulings and how the Constitutional Court takes them into account. ( http://www.const-court.be/)
 CJEU, 1st March 2011, ASBL (Test-achat ASBL).
 CJEU, 13 April 2010, Bressol and Chaverot, C-73/08. This ruling is the answer to the preliminary reference of 22 February 2008 by the Belgian Constitutional Court.
 CJEU, 6 October 2010, Base NV, Euphony Benelux NV, Mobistar SA, Uninet International NV, T2 Belgium NV, KPN Belgium NV.
 CJEU, 21 October 2010, I.B. (European Arrest Warrant II). This ruling is the answer to the preliminary reference of 24 July 2009 by the Belgian Constitutional Court.
 Expression by Marc Verdussen, "La Cour constitutionnelle, partenaire de la Cour de justice de l'Union européenne", op.cit., 2011, pp. 81-109.
 Belgian Constitutional Court, 27 January 2011, No 7/2011. No English translation available.
 Belgian Constitutional Court, 24 February 2011, No 28/2011.
 On the importance of criminal law in the EU, see Droit pénal de l'Union européenne au lendemain du Traité de Lisbonne, G. Giudicelli-Delage, C. Lazerges (ed.), Paris, SLC, 2012, 336p. (vol. No 28)
 The operative part of the decision of 24 February 2011 reads as follows: "Article 8 of the Law of 19 December 2003 relating to the European arrest warrant violates Articles 10 and 11 of the Constitution if it is interpreted as not permitting the Court to subject the surrender of a person, who is of Belgian nationality or residing in Belgium, who is the subject of an arrest warrant for the purposes of the execution of a sentence imposed in absentia, without the concerned person being informed of the date and place of the hearing preceding the conviction from which they can appeal, on the condition that that person be returned to Belgium in order to serve there the custodial sentence or detention order imposed by a final judgment against that person in the issuing State.
- The same provision does not violate Articles 10 and 11 of the Constitution if it interpreted as permitting the Court to subject the surrender of a person, who is of Belgian nationality or residing in Belgium, who is the subject of an arrest warrant for the purposes of the execution of a sentence imposed in absentia, without the concerned person being informed of the date and place of the hearing preceding the conviction from which they can appeal, on the condition that that person be returned to Belgium in order to serve there the custodial sentence or detention order imposed by a final judgment against that person in the issuing State (Unofficial translation).
 Belgian Constitutional Court, 31st May 2011, No 89/2011.
 Of particular interest are B.12 and B.13 paragraphs: "In view of the reasons set out by the Court of Justice in its 1 March 2011 judgment, the Constitutional Court decided that the differential treatment could not be reasonably justified and that the Law complained of should therefore be repealed. Moreover, the Court decided, in view of the transitional period posited by the Court of Justice, to retain the effects of the repealed legislative provisions until 21 December 2012".
English summary on the Constitutional Court's website: http://www.const-court.be/cgi/arrets_popup.php?lang=en&ArrestID=3167 . "B.12. In view of the reasons set out by the Court of Justice in its 1 March 2011 judgment, in particular paragraphs 30 to 32 - that find a violation of the principle of equality between men and women enshrined in Articles 21 and 23 of the Charter of Fundamental Rights of the European Union - , the differential treatment could not be reasonably justified. This finding concerns Articles 3 of the concerned law as well as Article 4 that sets up a transitional period; it is also related to other provisions of the law of 21st December 2007,given their connection to Articles 3 and 4. B. 13. The first argument is accepted. As a consequence, the concerned law must be repealed in its entirety." (Unofficial translation)