When the six founding European states created the European Economic Community in 1957 they did so in the form of an international treaty (known as the Treaty of Rome) that was binding between them. That treaty also created the European Court of Justice. In an important ruling in 1964, the Court said that the states had agreed to limit their sovereign rights in the areas covered by the treaty and could not adopt national laws that were incompatible with European law. This principle of ‘primacy’ or supremacy of EU law has been accepted and applied by national courts including the UK courts.
The Court of Justice does not, however, have any power to strike down national law; this is a task for the national courts. The national courts will, however, seek to resolve the conflict through interpretation. But UK courts are required not to enforce UK laws to the extent that they are incompatible with EU obligations.
For more information on the EU institutions as a whole, go to this explainer here.
Read this piece, Where does Brexit leave UK law? by Professor Catherine Barnard for more analysis on this issue.View all facts