Constitutional Courts as European Union courts. The current and potential use of EU law as a yardstick for constitutional review

In principle, constitutional courts do not review questions of domestic compliance with EU law, as these are considered to be outside their jurisdiction. But there are several exceptions in which EU law serves as a yardstick for constitutional review. This article focuses on these exceptions from a comparative perspective. First, it describes the ‘state of the art’ by examining whether and to what extent constitutional courts already use EU law as a standard for their decisions and invalidate domestic legislation or courts’ decisions that conflict with EU law. Then, it explores the limits within which EU law can be invoked as a yardstick for constitutional review without jeopardizing the principle of primacy of EU law. Finally, it argues that constitutional courts should not be afraid to embrace EU law as a standard for review: Doing so would not only contribute to a better protection of fundamental rights and the rule of law in Europe, but would also further the interests of constitutional courts.