Depending on the constitutional tradition of member states, different solutions have been developed to adapt questions of incompatibility between State law and Union law to one another. EU law is accepted as having supremacy over the law of member states, but not all member states share the ECJ's analysis on why EU law takes precedence over state law if there is a conflict.
Belgium In its ruling of 27 May 1971, often nicknamed the "Franco-Suisse Le Ski ruling" or "Cheese Spread ruling" (), the
Belgian Court of Cassation ruled that self-executing treaties prevail over national law, and even over the
Belgian Constitution. In 2016, the Belgian Constitutional Court ruled that there is a limit to the primacy of EU law over the Belgian Constitution. Mimicking the
Identitätsvorbehalt jurisprudence of the German Constitutional Court, it ruled that the core of Belgium's constitutional identity cannot be trumped by EU law.
Czech Republic 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.
France 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
Council of State, 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
Court of Cassation ; in the case of ''Administration des Douanes v Société 'Cafes Jacques Vabre' et SARL Wiegel et Cie
, 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'' by deciding to follow the reasoning used by the Cour de cassation.
Germany In its
Solange I decision (1970), Germany's
Federal Constitutional Court articulated constitutional limits on Germany's integration into the European Union. The Court expressed concern that Europe lacked either a “democratically legitimate parliament directly elected by general suffrage” or a “codified catalogue of fundamental rights.” Consequently, it argued that independent review was necessary to ensure that the unamendable protections of
German Basic Law are upheld. In response, the
European Parliament,
Council, and
Commission issued a joint declaration emphasizing the “prime importance” of fundamental rights, as derived from both member states’ constitutions and the
European Convention on Human Rights in 1977. Noting this development in
Solange II, (1986) the German Constitutional Court held that
so long as () 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 Solange cases engendered a “cooperative relationship” between the Federal Constitutional Court and the ECJ. 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.
Lithuania 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.
Malta 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.
Netherlands The
Constitution of the Kingdom of the Netherlands (Dutch:
Grondwet) functions as a codification of political practice rather than a normative collection of robust guarantees. As in the United Kingdom, the legislature has broad authority to define constitutional law as well as limits on the protection of rights. The Grondwet enshrines neither an absolute right to a fair trial, life, or property, and it provides few guidelines for the formation of governments. Moreover, judicial review of the constitutionality of parliamentary acts was prohibited in 1848.
Poland While Poland rejects the idea of Primacy of European Union law as defined in case law on basis of the ruling K 18/04 of
The Constitutional Tribunal it follows article 91. sec 3. of Constitution which gives international organization ability to formulate law that can overwrite Polish statutes. The law has priority in conflict with the statutes if the law is concurrent to the text of the treaty that constitutes that international organization. The ratified international agreement also overwrites the statutes if the statute is impossible to reconcile with the agreement on basis of article 91. sec 2. The tribunal has also ruled that EU law can not override the Polish constitution. In a conflict between EU law and the constitution, constitution prevails. Poland can then make a sovereign decision as to how conflict EU law vs Constitution should be resolved (by changing the constitution, seeking to change the EU law or leaving the EU). ==United Kingdom as a former member state==