Does EU law take precedence over UK law?
In an important ruling in 1964, the European Court of Justice said that member states had agreed to limit their sovereign rights in areas covered by EU treaties and could not adopt national laws that were incompatible with European law. This principle of the ‘primacy’ of EU law means that any conflicting national law in areas covered by the EU treaties cannot be enforced. However, the Court of Justice does not have any power to strike down national law – this is a task for national courts.
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.