The primacy of European Union law (sometimes referred to as supremacy or precedence of European law) is a legal principle of rule according to higher law establishing precedence of European Union law over conflicting national laws of EU member states.
The principle was derived from an interpretation of the European Court of Justice, which ruled that European law has priority over any contravening national law, including the constitution of a member state itself. For the European Court of Justice, national courts and public officials must disapply a national norm that they consider not to be compliant with the EU law.