Primacy of European Union law

In its ruling of 27 May 1971, often nicknamed the "Franco-Suisse Le Ski ruling" or "Cheese Spread ruling" (Dutch: Smeerkaasarrest), the Belgian Court of Cassation ruled that self-executing treaties prevail over national law, and even over the Belgian Constitution.[10]

As a consequence, EU regulations prevail over Belgian national law. EU directives do not prevail unless they are converted to national law.

Article 10 of the Constitution of the Czech Republic states that every international treaty ratified by the Parliament of the Czech Republic is part of the Czech legislative order and takes precedence over all other laws.[11]

Like many other countries within the civil law legal tradition, France's judicial system is divided between ordinary and administrative courts. The ordinary courts accepted the supremacy of EU law in 1975, but the administrative courts accepted the doctrine only in 1990. The supreme administrative court, the Conseil d'Etat, had held that as the administrative courts had no power of judicial review over legislation enacted by the French Parliament, they could not find that national legislation was incompatible with Union law or give it precedence over a conflicting State law. That was in contrast to the supreme ordinary court, the Cour de cassation; in the case of Administration des Douanes v Société 'Cafes Jacques Vabre' et SARL Wiegel et Cie,[12] it ruled that precedence should be given to Union law over State law in line with the requirements of the Article 55 of the French Constitution, which accorded supremacy to ratified international treaty over State law. The administrative courts finally changed their position in the case of Raoul Georges Nicolo[13] by deciding to follow the reasoning used by the Cour de cassation. However, both ordinary courts and administrative courts still reject the primacy of EU law over the French constitution.

In Solange II,[14] the German Constitutional Court held that so long as (German: solange) EU law had a level of protection of fundamental rights that is substantially in concurrence with the protections afforded by the German constitution, it would no longer review specific EU acts in light of that constitution.

The Third Amendment of the Constitution of Ireland explicitly provided for the supremacy of EU law in the Republic of Ireland by providing that no other provision of the Irish constitution could invalidate laws enacted if they were necessitated by membership of the European Communities. In Crotty v. An Taoiseach, the Irish Supreme Court held that the ratification of the Single European Act by the Republic of Ireland was not necessitated by membership of the European Communities and so could be subject to review by the courts.

In Frontini v. Ministero delle Finanze,[15] the plaintiff sought to have a national law disregarded without having to wait for the Italian Constitutional Court do so. The ECJ ruled that every State's supreme court must apply Union law in its entirety.

The Lithuanian Constitutional Court concluded on 14 March 2006 in case no. 17/02-24/02-06/03-22/04, § 9.4 in Chapter III, that EU law has supremacy over ordinary legal acts of the Lithuanian Parliament but not over the Lithuanian constitution. If the Constitutional Court finds EU law to be contrary to the constitution, the former law loses its direct effect and shall remain inapplicable.[16]

Article 65 of the Maltese constitution provides that all laws made by Parliament must be consistent with EU law and Malta's obligations deriving from its Treaty of Accession.[17]

The Constitutional Tribunal of Poland ruled that while EU law may override member state statutes, it does not override the Polish constitution. In a conflict between EU law and the constitution, Poland can make a sovereign decision as to how this conflict should be resolved (by changing the constitution, leaving the EU or seeking to change the EU law).[18]

The United Kingdom was a member state of the European Union and its predecessor the European Communities from 1 January 1973 until 31 January 2020. During this time the issue of EU law taking precedence over national law was a significant issue and a cause for debate both among politicians and even in the judiciary.

In R v Secretary of State for Transport, ex p Factortame Ltd, the House of Lords ruled that courts in the United Kingdom had the power to "disapply" acts of parliament if they conflicted with EU law. Lord Bridge held that Parliament had voluntarily accepted this limitation of its sovereignty and was fully aware that even if the limitation of sovereignty was not inherent in the Treaty of Rome, it had been well established by jurisprudence before Parliament passed the European Communities Act 1972.[19]

If the supremacy within the European Community of Community Law over the national law of member states was not always inherent in the EEC Treaty it was certainly well established in the jurisprudence of the Court of Justice long before the United Kingdom joined the Community. Thus, whatever limitation of its sovereignty Parliament accepted when it enacted the European Communities Act 1972 was entirely voluntary. Under the terms of the 1972 Act it has always been clear that it was the duty of a United Kingdom court, when delivering final judgment, to override any rule of national law found to be in conflict with any directly enforceable rule of Community law.

In 2011 the UK Government, as part of the Conservative–Liberal Democrat coalition agreement following the 2010 UK general election, passed the European Union Act 2011 in a attempt to address the issue by inserting a sovereignty clause.[20] The clause was enacted in section 18 which says:

Directly applicable or directly effective EU law (that is, the rights, powers, liabilities, obligations, restrictions, remedies and procedures referred to in section 2(1) of the European Communities Act 1972) falls to be recognised and available in law in the United Kingdom only by virtue of that Act or where it is required to be recognised and available in law by virtue of any other Act.

However, in the 2014 case of R (HS2 Action Alliance Ltd) v Secretary of State for Transport, the Supreme Court of the United Kingdom said:[21][22]

The United Kingdom has no written constitution, but we have a number of constitutional instruments. They include Magna Carta, the Petition of Right 1628, the Bill of Rights and (in Scotland) the Claim of Rights Act 1689, the Act of Settlement 1701 and the Act of Union 1707. The European Communities Act 1972, the Human Rights Act 1998 and the Constitutional Reform Act 2005 may now be added to this list. The common law itself also recognises certain principles as fundamental to the rule of law. It is, putting the point at its lowest, certainly arguable (and it is for United Kingdom law and courts to determine) that there may be fundamental principles, whether contained in other constitutional instruments or recognised at common law, of which Parliament when it enacted the European Communities Act 1972 did not either contemplate or authorise the abrogation.

At 23:00 GMT (00:00 CET in Brussels) on 31 January 2020, the United Kingdom became the first member state to formally leave the European Union after 47 years of membership under the terms of the Brexit withdrawal agreement. At the same time, the European Communities Act 1972 (ECA 1972), the piece of legislation that incorporated EU law (Community law as it was in 1972) into the domestic law of the United Kingdom, was repealed by the European Union (Withdrawal) Act 2018, although the effect of the 1972 Act was saved by the provisions of the European Union (Withdrawal Agreement) Act 2020 to enable EU law to continue to have legal effect within the UK until the end of the implementation period, which ended on the 31 December 2020. Since the implementation period has now ended, EU law no longer applies to the UK. However the principle of the supremacy of EU law applies to the interpretation of retained EU law.[23]