Primacy of European Union law
The primacy of European Union law (sometimes referred to as supremacy) is an EU law principle that when there is conflict between European law and the law of Member States, European law prevails; the norms of national law have to be set aside. This principle was developed by the European Court of Justice, and, as interpreted by that court, it means that any norms of European law always take precedence over any norms of national law, including the constitutions of member states. Although national courts generally accept the principle in practice, most of them disagree with this extreme interpretation and reserve the right, in principle, to review the constitutionality of European law under national constitutional law.
In Costa v. ENEL. Mr Costa was an Italian citizen opposed to the nationalising of energy companies. Because he had shares in a private corporation subsumed by the nationalised company, ENEL, he refused to pay his electricity bill in protest. In the subsequent suit brought to Italian courts by ENEL, he argued that nationalisation infringed EC law on the State distorting the market. The Italian government believed that this was not even an issue that could be complained about by a private individual, since it was a national law decision to make. The European Court of Justice ruled in favour of the government, because the relevant Treaty rule on an undistorted market was one on which the Commission alone could challenge the Italian government. As an individual, Mr Costa had no standing to challenge the decision, because that Treaty provision had no direct effect. But on the logically prior issue of Mr Costa's ability to raise a point of EC law against a national government in legal proceeding before the courts in that member state the ECJ disagreed with the Italian government. It ruled that EC law would not be effective if Mr Costa could not challenge national law on the basis of its alleged incompatibility with EC law.
It follows from all these observations that the law stemming from the treaty, an independent source of law, could not, because of its special and original nature, be overridden by domestic legal provisions, however framed, without being deprived of its character as community law and without the legal basis of the community itself being called into question.
In other cases, countries write the precedence of Union law into their constitutions. For example, the Constitution of Ireland contains a clause that "No provision of this Constitution invalidates laws enacted, acts done or measures adopted by the State which are necessitated by the obligations of membership of the European Union or of the Communities".
- C-106/77, Simmenthal  ECR 629, duty to set aside provisions of national law which are incompatible with Union law.
- C-106/89 Marleasing  ECR I-7321, National law must be interpreted and applied, insofar as possible, so as to avoid a conflict with a Community rule.
Article I-6 of the European Constitution stated that "The Constitution and law adopted by the institutions of the Union in exercising competences conferred on it shall have primacy over the law of the Member States." However, the constitution was never ratified but its replacement, the Treaty of Lisbon included the following declaration on primacy:
17. Declaration concerning primacy
The Conference recalls that, in accordance with well settled case law of the Court of Justice of the European Union, the Treaties and the law adopted by the Union on the basis of the Treaties have primacy over the law of Member States, under the conditions laid down by the said case law.
The Conference has also decided to attach as an Annex to this Final Act the Opinion of the Council Legal Service on the primacy of EC law as set out in 11197/07 (JUR 260):
Opinion of the Council Legal Service
of 22 June 2007
It results from the case-law of the Court of Justice that primacy of EU law is a cornerstone principle of Union law. According to the Court, this principle is inherent to the specific nature of the European Community. At the time of the first judgment of this established case law (Costa/ENEL,15 July 1964, Case 6/641 (1) there was no mention of primacy in the treaty. It is still the case today. The fact that the principle of primacy will not be included in the future treaty shall not in any way change the existence of the principle and the existing case-law of the Court of Justice.
(1) It follows (...) that the law stemming from the treaty, an independent source of law, could not, because of its special and original nature, be overridden by domestic legal provisions, however framed, without being deprived of its character as Community law and without the legal basis of the Community itself being called into question.
Depending on the constitutional tradition of member states, different solutions have been developed to adapt questions of incompatibility between national law and EU law to one another. Union law is accepted as having supremacy over the law of member states, but not all member states share the ECJ's analysis of why EU law takes precedence over national law when there is a conflict.
Article 10 of the Constitution of the Czech Republic states that every international treaty ratified by parliament of the Czech Republic is a part of the Czech legislative order and takes precedence over all other laws.
Like many countries within the civil law legal tradition, France's judicial system is divided between ordinary and administrative courts. While the ordinary accepted the supremacy of EU law in 1975, the administrative only accepted the doctrine in 1990. Before this the supreme administrative court, the Conseil d'Etat, 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 EC law or give EC law precedence over conflicting national law. This was in contrast to the supreme court of the ordinary courts, the Cour de cassation, which in the case of Administration des Douanes v Société 'Cafes Jacques Vabre' et SARL Wiegel et Cie, ruled that precedence should be given to EC law over national law in line with the requirements of the Article 55 of the Constitution which accorded supremacy to ratified international treaty over national law. The administrative courts finally changed their position in the case of Raoul Georges Nicolo when they decided to follow the reasoning used by the Cour de cassation.
In Solange II the German Constitutional Court held that so long as (German: solange) EU law had a level of protection of fundamental rights substantially in concurrence with the protections afforded by the German constitution they would not longer review specific Union acts in light of their own constitution.
The Third Amendment of the Constitution of Ireland explicitly provided for the supremacy of EU law within the Republic of Ireland by providing that no other provision of the Irish constitution could invalidate laws enacted which was necessitated by membership of the then European Communities. In Crotty v. An Taoiseach the Irish Supreme Court held that the ratification of the Single European Act by Ireland was not necessitated by membership of the European Communities and could therefore be subject to review by the courts.
In Frontini v. Ministero delle Finanze, 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 national court must apply Community Law in its entirety.
The Lithuanian Constitutional Court concluded with its Ruling dated 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 Constitution. In case when the Constitutional Court finds the EU law contrary to the Lithuanian Constitution, the Union law loses its direct effect and shall remain inapplicable.
The Constitutional Tribunal of Poland ruled that while EU law may override national statutes, it does not override the Constitution. In cases of a conflict between EU law and the Constitution, Poland can make a sovereign decision as to how this conflict should be resolved (i.e. by changing the Constitution, leaving the EU or seeking to change the EU law).
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 where they conflicted with EU law. Lord Bridge held that Parliament had voluntarily accepted this limitation of its sovereignty, being 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.
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.
However, in the 2014 case of R (HS2 Action Alliance Ltd) v Secretary of State for Transport, the UK Supreme Court said:
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.
In its ruling of 22 May 1971, famously nicknamed "het Smeerkaasarrest" (Dutch for "the cheese spread ruling"), the Belgian Court of Cassation ruled that self-executing treaties prevail over national law, including the Belgian constitution. Thus, regulations prevail over national law. Directives only prevail if converted to national law.
- Thoburn v Sunderland City Council (2002)
- Van Gend en Loos v Nederlandse Administratie der Belastingen (1963)
- Supremacy Clause in United States law
- Craig, Paul; De Burca, Grainne (2015). EU Law: Text, Cases and Materials (6th ed.). Oxford: Oxford University Press. pp. 266ff. ISBN 978-0-19-871492-7.
- Case 6/64, Flaminio Costa v. ENEL  ECR 585, 593
- now found in Art. 86 and Art. 87
- "But this obligation does not give individuals the right to allege, within the framework of community law... either failure by the state concerned to fulfil any of its obligations or breach of duty on the part of the commission."
- Case 6/64, Flaminio Costa v. ENEL  ECR 585, 593
-  2 CMLR 336.
-  1 CMLR 173.
- Re Wuensche Handelsgesellschaft, BVerfG decision of 22 October 1986  3 CMLR 225,265).
-  2 CMLR 372.
- Ruling of the Lithuanian Constitutional Court dated 14 March 2006 in case no. 17/02-24/02-06/03-22/04
- "Verdict of the Constitutional Tribunal of Poland of May 11th, 2005"; K 18/04 Archived 3 March 2016 at the Wayback Machine.
- Lord Bridge, 1991, Appeal Cases 603, 658; quoted in Craig, Paul; de Búrca, Gráinne (2007). EU Law, Text, Cases and Materials (4 ed.). Oxford: Oxford University Press. pp. 367–368. ISBN 978-0-19-927389-8.
-  UKSC 3 at , per Lords Neuberger and Mance
- See also Mark Elliot's analysis at: http://ukconstitutionallaw.org/2014/01/23/mark-elliot-reflections-on-the-hs2-case-a-hierarchy-of-domestic-constitutional-norms-and-the-qualified-primacy-of-eu-law/