Concept and legal classification of the European Constitution
The European Constitution – also known as the Treaty establishing a Constitution for Europe (TCE or EU Constitutional Treaty) – refers to the attempt within the European Union (EU) to consolidate the legal and institutional foundations of the Community in a single constitutional document. The aim was to codify and modernise the existing treaties and to strengthen the coherence, capacity to act, and democratic legitimacy of European integration.
The term differs from an actual constitution in the sense of constitutional law, since the Member States remain sovereign and the EU does not acquire an independent, state-like constitutional authority. Thus, the Constitutional Treaty constitutes an international agreement between the Member States under international law.
Historical development
Predecessors and motivation for the constitutional project
Discussions about a European constitution date back to the beginnings of European unification. As early as 1952, the Treaty establishing the European Defence Community was drafted as a constitution-like document but was not ratified. The growing importance of the European Communities and the expansion of competences created a need for a clearer and more unified constitutional system.
With the Treaty of Maastricht (1992), the Treaty of Amsterdam (1997), and the Treaty of Nice (2001), the EU was further developed, though its structures and decision-making processes were often criticised for being complex, confusing, and insufficiently citizen-oriented. The European Convention (2002–2003) ultimately drafted a European Constitution.
Treaty establishing a Constitution for Europe (TCE)
The Treaty establishing a Constitution for Europe was signed in Rome on 29 October 2004. The main focus of the treaty was especially:
- The consolidation of all existing EU treaties into one document
- Clarification of the legal foundations of the EU
- Introduction of legal personality for the Union
- A greater emphasis on democratic and citizen-oriented elements (e.g. through the introduction of the European Citizens’ Initiative)
- Increased efficiency of decision-making processes by abolishing the previous pillar structure
Failure and aftermath
The ratification of the treaty failed in 2005 due to negative referendums in France and the Netherlands. The constitutional project was then discontinued in this form. However, many elements of the treaty were incorporated into the Treaty of Lisbon (2007), which entered into force on 1 December 2009 and, as the ‘Reform Treaty’ of the EU, fulfils a partial constitutional function.
Substantive structure of the Constitutional Treaty
Structure
The text of the European Constitution was organised into four parts:
- Principles and values (institutional order, competences, fundamental rights)
- Charter of Fundamental Rights of the European Union
- Policies and functioning of the Union
- Final, transitional, and amendment provisions
Legal foundations and innovations
The Constitutional Treaty did not replace national constitutions, but established a higher legal order at the level of the Member States. Key legal innovations included:
- Legal personality of the EU: For the first time, the EU was expressly designated as an international organisation with legal personality and could conclude its own treaties with third countries.
- Division of competences: The distribution of competences between the Union and the Member States was explicitly set out (exclusive, shared, and supporting competences).
- Legal principles: Clear definition of principles such as subsidiarity, proportionality, and primacy of EU law.
- Institutional reforms: Strengthening of the European Parliament, new posts such as President of the European Council, creation of the EU Foreign Minister (later amended to High Representative).
- Charter of Fundamental Rights: For the first time, the Charter of Fundamental Rights of the European Union proclaimed in 2000 became part of ‘primary law’, i.e. binding on all Member States.
Legal assessment and significance
Constitutional law dimensions
Legally, the Constitutional Treaty was an international treaty with a constitution-shaping effect, but did not technically constitute a ‘constitution’ in the sense of national constitutional law. It would have replaced the previous treaties (Treaty on European Union, EC Treaty, Euratom Treaty) and provided a unified structure for the Union.
Relationship to national constitutions
National sovereignty would not have been abolished by the European Constitution. The Member States would have retained their own constitutions, but in the event of a conflict, their provisions would have been subordinate to the primacy of European constitutional law. National courts, particularly constitutional courts, would have continued to ensure that the EU did not exceed its competences (ultra vires review).
Democratic and rule of law implications
The stronger involvement of the European Parliament, as well as new participatory rights for citizens, were intended to improve the EU’s democratic legitimacy. The anchoring of fundamental rights aimed to enhance legal protection for Union citizens. However, the extent of delegated competences and the transparency of decision-making processes were viewed critically.
European Constitution in the light of European constitutional law
Strict and broad concept
Even after the failure of the treaty, the term ‘European constitutional order’ is often used in academic literature. This refers to the treaties and primary law that form the constitutional foundations of the EU. The Treaty of Lisbon adopted and further developed many elements of the Constitutional Treaty.
Judicial review and enforcement of the law
The European Court of Justice (ECJ) is responsible for the interpretation and application of European primary law. Since the entry into force of the Treaty of Lisbon, the Charter of Fundamental Rights has been binding for all EU institutions and Member States when implementing EU law. In addition, national courts continue to exercise control, particularly regarding the preservation of constitutional identity.
Conclusion and current significance
Although the European Constitution never formally entered into force, its contents have significantly shaped today’s primary law of the European Union. The comprehensive reforms of the Treaty of Lisbon are largely based on the work and concepts of the European Convention. The debate about a codified, unified European Constitution remains a central issue in the context of the further development of the EU and its institutional, democratic, and legal foundations. Legally, the European Constitution is therefore to be understood as a milestone and catalyst in the progressive constitutionalisation of the European legal area.
Frequently asked questions
What legal differences exist between the European Constitution and the existing EU treaties?
The European Constitution, officially the ‘Treaty establishing a Constitution for Europe’, was designed to consolidate the existing European treaties—especially the Treaty on European Union (TEU) and the Treaty establishing the European Community (TEC)—into a single document and partially replace them. Legally, the Constitution would have stood as primary law at the top of the EU’s hierarchy of legal sources and would have been directly applicable. Its aim was to make the Union’s legal foundations clearer, more transparent, and more accessible. Compared with the existing treaties, the Constitution would have provided a consolidated codification of fundamental legal principles, an explicit definition of the EU’s powers, and a unified structure. In addition, various protocols and declarations, previously scattered, would have been integrated into the constitutional text. A major change was the introduction of legal terms such as ‘law’ and ‘framework law’, but these were not retained in subsequent amending treaties such as the Treaty of Lisbon.
What legal consequences would ratification of the European Constitution have had for the sovereignty of the Member States?
The ratification of the European Constitution would have had significant effects on the sovereignty of the Member States by expressly regulating the distribution of competences between the EU and the Member States. The Constitution stipulated the explicit codification of the principles of conferral of powers, subsidiarity, and proportionality. This meant that the EU could only act in policy areas expressly conferred upon it by the Constitution. At the same time, it would have provided Member States with a mechanism to review compliance with these principles (subsidiarity complaint). New treaty amendments would also have been possible through a simplified procedure, making it easier to adapt to political necessities, but also potentially lowering the threshold for competence shifts. The Charter of Fundamental Rights would have become a binding part of primary law, directly overriding national legislation in many cases.
To what extent would the European Constitution have changed the relationship between EU law and national law?
With the European Constitution, the primacy of EU law over national law would have been expressly enshrined, a principle that had previously only been developed through the case law of the European Court of Justice (ECJ). Through formal enshrinement in the constitutional text, the relationship between EU law and national law would have shifted further in favour of Union law; national courts would have been expressly required not to apply any conflicting national law. National constitutions would also have been subordinate to the constitutional text, except for their fundamental constitutional identities, which would still have been respected. This would have been particularly significant in view of constitutional reservations of individual Member States (e.g. the Federal Constitutional Court in Germany), since any conflicts could then have been resolved directly on the basis of the constitutional text.
How would compliance with the European Constitution have been legally supervised?
Compliance with the European Constitution would have been monitored primarily by the European Court of Justice (ECJ). The ECJ would have had the competence to determine the interpretation and application of constitutional provisions in a binding manner in all Member States. The Constitution also envisaged new rights of action, for example for national parliaments to complain of breaches of the subsidiarity principle. The right to bring actions against EU acts would have been extended to ensure stronger legal control. Specific sanction mechanisms would have been created for violations of the Constitution and the Charter of Fundamental Rights, thus strengthening the overall legal enforcement mechanisms.
What legal provisions regarding membership and withdrawal of states would the European Constitution have contained?
For the first time, the European Constitution would have created a formal legal framework for withdrawal from the EU (‘withdrawal clause’). This would have allowed a Member State to declare its withdrawal in accordance with its own constitutional requirements, following which negotiations on the terms of withdrawal would have commenced with the Union. The Constitution would also have transparently regulated the admission criteria for new members and established a clear procedure for the suspension of membership rights in the event of serious breaches of the basic principles of the Union. These provisions were later largely—particularly the withdrawal clause—incorporated into the Treaty of Lisbon.
How would the European Constitution have affected fundamental rights and their legal enforcement in the EU?
With the European Constitution, the Charter of Fundamental Rights of the European Union would have been fully and legally integrated into primary law. This would have meant that all EU institutions and Member States, when implementing Union law, would have been directly bound by the fundamental rights. Individual enforcement of these rights through individual actions before the ECJ would have been strengthened and expanded. The scope of application would have covered all areas of EU law, while purely national matters would have remained outside its remit. This legal anchoring of fundamental rights was intended to provide a uniform and high level of protection within the EU.
What specific legal provisions regarding amendments to the European Constitution would have been envisaged?
The European Constitution would have introduced a multi-stage and differentiated procedure for amending its provisions. Fundamental amendments would only have been possible by unanimous decision of the European Council followed by ratification in all Member States. For technical adaptations and institutional changes, however, a simplified procedure would have been foreseen. These mechanisms would have provided greater flexibility in dealing with necessary reforms on the one hand, but also protection from undesired shifts in competences on the other.
