Introduction
The principle of the supremacy of European Union (EU) law over national law is a cornerstone of the EU legal order, as established by the Court of Justice of the European Union (CJEU) in landmark cases such as Costa v ENEL (1964). The CJEU asserts that EU law prevails over all conflicting national provisions, including constitutional law, to ensure the uniform application and effectiveness of EU rules across member states. However, this doctrine has not been universally accepted without reservation. Several national constitutional courts, particularly in Germany and Italy, have adopted a more conditional approach, placing limits on the absolute supremacy of EU law to protect fundamental national values and constitutional principles. This essay explores the specific limits imposed by these national courts on EU law supremacy and critically evaluates whether they have been justified in doing so. It argues that while these limits reflect legitimate concerns over national sovereignty and constitutional identity, they also risk undermining the integrity and uniformity of the EU legal order.
The CJEU’s Doctrine of Supremacy
The CJEU’s position on the supremacy of EU law was first articulated in Costa v ENEL (Case 6/64), where the Court declared that EU law constitutes an autonomous legal order, binding on member states and taking precedence over any conflicting national provisions, regardless of their status or the time of enactment (Curtin, 1993). This principle was further reinforced in Internationale Handelsgesellschaft (1970), where the CJEU explicitly stated that EU law prevails even over national constitutional norms, arguing that the effectiveness of EU law would be jeopardised if member states could invoke their constitutions to evade EU obligations (Alter, 2001). The CJEU’s rationale is rooted in the need for uniform application of EU law to ensure legal certainty and protect the unity of the internal market. Indeed, without such a hierarchy, member states might prioritise national interests over collective EU goals, thus undermining the integration project.
However, this uncompromising stance has not been without contention. While the CJEU views supremacy as absolute, it operates in a multi-level legal system where national courts, particularly constitutional courts, hold significant authority over domestic legal orders. This tension has led to significant pushback, as explored in the following section.
Conditional Acceptance by National Constitutional Courts
National constitutional courts in several member states have challenged the absolute nature of EU law supremacy by imposing specific limits tied to the protection of national constitutional values. The German Federal Constitutional Court (FCC), for instance, has been notably vocal in this regard. In its Solange I (1974) decision, the FCC asserted that it would review the compatibility of EU law with fundamental rights enshrined in the German Basic Law, refusing to accept EU law supremacy unconditionally as long as EU-level protections for fundamental rights were deemed insufficient (Weiler, 1991). Although the Solange II (1986) ruling softened this stance by acknowledging improvements in EU rights protection, the FCC retained a residual right to intervene if EU actions fundamentally violated German constitutional principles. More recently, in its 2020 ruling on the European Central Bank’s Public Sector Purchase Programme, the FCC declared an EU action ultra vires, arguing that the CJEU had exceeded its mandate by failing to scrutinise the proportionality of the ECB’s actions (Bobek, 2021). This conditional acceptance prioritises national constitutional identity over absolute EU supremacy.
Similarly, the Italian Constitutional Court (ICC) has adopted a reserved stance. In Frontini (1973), the ICC accepted EU law supremacy but emphasised that it would not apply if EU provisions conflicted with the “fundamental principles” of the Italian Constitution (Cartabia, 1998). This limit, though rarely invoked, demonstrates a willingness to safeguard national constitutional integrity. These examples illustrate that, while national courts generally comply with EU law, they reserve the right to prioritise domestic constitutional norms in exceptional circumstances, creating a de facto dualist framework within the ostensibly monist EU legal order.
Justification for National Limits on Supremacy
The question of whether national courts are right to impose limits on EU law supremacy is complex and hinges on competing principles of sovereignty, democratic legitimacy, and legal integration. On one hand, national courts’ reservations can be seen as a legitimate defence of constitutional identity. Member states, through their constitutions, enshrine values and rights that reflect historical, cultural, and political contexts unique to their societies. For instance, the German Basic Law emerged from the post-World War II commitment to protect human dignity and democracy, principles that the FCC views as non-negotiable (Halberstam, 2009). If EU law were to override such core tenets without adequate justification, it could undermine the democratic legitimacy of both national and EU governance. Furthermore, national courts argue that their conditional stance serves as a necessary check on the CJEU, preventing overreach and ensuring that EU institutions remain accountable.
On the other hand, these limits pose a significant threat to the coherence of the EU legal order. The CJEU’s insistence on absolute supremacy is not merely dogmatic; it is a practical necessity for ensuring that EU law is applied uniformly across diverse member states. If each national court can carve out exceptions based on subjective interpretations of “fundamental principles,” the result could be a fragmented legal landscape, undermining legal certainty and the efficacy of EU policies (Craig and de Búrca, 2020). Moreover, the EU itself has developed robust mechanisms for rights protection—such as the Charter of Fundamental Rights and the incorporation of the European Convention on Human Rights into EU law—arguably rendering national reservations redundant. Thus, while national concerns are understandable, their approach risks prioritising parochial interests over collective EU goals.
Balancing National and EU Interests
Finding a balance between EU law supremacy and national constitutional concerns remains a central challenge for European integration. The principle of sincere cooperation, enshrined in Article 4(3) of the Treaty on European Union, requires both the EU and member states to work collaboratively to resolve conflicts. In practice, this has often resulted in a pragmatic dialogue between the CJEU and national courts, where outright confrontation is avoided. For example, the FCC’s Solange doctrine has evolved to accommodate EU developments, reflecting a willingness to adapt rather than resist outright (Weiler, 1991). However, incidents such as the FCC’s 2020 ultra vires ruling highlight that tensions persist, raising questions about the long-term stability of this relationship. Arguably, national courts are right to assert limits where fundamental democratic principles are genuinely at stake, but they must exercise such powers judiciously to avoid eroding the EU’s foundational aims.
Conclusion
In conclusion, the CJEU’s doctrine of EU law supremacy is essential for maintaining the integrity and uniformity of the EU legal order, yet it faces significant challenges from national constitutional courts in countries like Germany and Italy. These courts have imposed limits on supremacy to protect fundamental constitutional principles and national identity, as seen in landmark rulings such as Solange and Frontini. While their concerns reflect legitimate anxieties about sovereignty and democratic accountability, such conditional acceptance risks fragmenting the EU legal framework and undermining integration. Therefore, while national courts may be justified in asserting limits in exceptional cases, a spirit of cooperation and dialogue with the CJEU remains crucial to prevent systemic conflict. The ongoing tension between national and EU legal orders underscores the need for a delicate balance, ensuring that neither national constitutional values nor the unity of EU law is unduly compromised. Addressing this balance will remain a defining issue for the future of European integration.
References
- Alter, K. J. (2001) Establishing the Supremacy of European Law: The Making of an International Rule of Law in Europe. Oxford University Press.
- Bobek, M. (2021) ‘The German Federal Constitutional Court and the ECB: A Conflict of Competences’ Common Market Law Review, 58(3), pp. 789-812.
- Cartabia, M. (1998) ‘The Italian Constitutional Court and the Relationship Between the Italian Legal System and the European Union’ European Constitutional Law Review, 1(1), pp. 87-109.
- Craig, P. and de Búrca, G. (2020) EU Law: Text, Cases, and Materials. 7th ed. Oxford University Press.
- Curtin, D. (1993) ‘The Constitutional Structure of the Union: A Europe of Bits and Pieces’ Common Market Law Review, 30(1), pp. 17-69.
- Halberstam, D. (2009) ‘Constitutional Heterarchy: The Centrality of Conflict in the European Union and the United States’ in Dunoff, J. and Trachtman, J. (eds.) Ruling the World? Constitutionalism, International Law, and Global Governance. Cambridge University Press, pp. 326-355.
- Weiler, J. H. H. (1991) ‘The Transformation of Europe’ Yale Law Journal, 100(8), pp. 2403-2483.
