In the context of the EU, it has long been known that the Union is not a self-authenticating entity.
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. News > UK > UK Politics 15 EU laws and regulations we will miss in post-Brexit Britain. As the UK is a member state within the EU, the EU’s law is hence a part of UK law. This principle of ‘primacy’ or supremacy of EU law has been accepted and applied by national courts including the UK courts.
For example, in one period criminal law matters or national security appear to fall wholly outside the scope of EC law and go to the core of national sovereignty; gradually Community law begins to encroach even upon these fields. The European Court would override the UK courts on appeals on areas of law which the EU has passed legislation. But UK courts are required not to enforce UK laws to the extent that … Once a law has been passed, the different countries agree to implement it, and allow it to override national law. A deep dive into the process of converting EU laws on everything from dog fur to flag days into UK law in time for Brexit day. Examples such as the 'Factortame' thing a whlie back, when Spain was given permission to fish on British waters, even though Margeret Thatcher passed a law that they weren't allowed. Does the UK accept this principle? EU institutions such as the commission, the parliament and the council are legally bound to uphold rights in the charter - as are EU governments whenever they apply EU law.
However when Spain appealed to the EU (though then I think it was the EEC/EC) they allowed it, as their law overrides the UK Law. Yes, and it has done since 1972, when Parliament passed the European Communities Act.
Any more examples? Where a conflict occurs EU Law would take precedence over the National Law and these laws are binding on national authorities.