The UK in a Changing Europe uses cookies to improve your browsing experience. We would also like to set optional analytical cookies to help us improve the website, but we will not set optional cookies unless you accept them.

The authoritative source for independent research on UK-EU relations

A Changing EU

Constitution

This fact was correct when it was updated on 22 Sep 2020

What is the European Court of Justice?

Formally known as the Court of Justice of the European Union, the European Court of Justice (ECJ) is the judicial authority of the EU, ruling on member states’ compliance with EU treaties, interpreting EU law and deciding on the legality of EU institutions’ actions. The court is divided into two: the Court of Justice and the General Court. The Court of justice has one judge from each Member State. There are also 9 Advocates General who are drawn from a range of states. The General Court has two judges from each state. While in transition, the UK Supreme Court must refer questions to the ECJ on the interpretation of the EU treaties and secondary legislation; all other courts have a discretion as to whether to refer such cases. All courts must refer cases on the validity of the actions of EU institutions.

Find out more – read our fact profile on the differences between the European Convention on Human Rights, the European Court of Human Rights and the European Court of Justice or read our explainer on the Court of Justice of the European Union.

More facts you may be interested in

When a new country joins the EU, does free movement apply straight away?

24 Sep 2020

What is the consent procedure?

24 Sep 2020

What is Article 49?

24 Sep 2020