The German Constitutional Court (GCC) in Karlsruhe is well known for its particular posture on questions relating to the European Union law. Now it has made a step sideways, saying that it has only limited jurisdiction in cases of ultra vires decisions of the EU institutions.
The GCC says that acts of EU institutions and bodies can only be reviewed by it “if the breach of EU competences by the EU body is obvious and the act in question leads to a structurally significant shift in the arrangement of competences between the member states and the European Union to the detriment of Member States”.
So the GCC implies a test for the seriousness and structural impact of breach of competences of the EU institution. I am not sure how this test can be made operational, though.
Also note that the decision relates not only to decisions of the EU Court of Justice (as suggested by EUobserver), but other EU institutions as well.