Poland’s membership has been one of the great success stories of the EU since the former communist-bloc country joined in 2004. Its economy has boomed. Its citizens have enjoyed freedoms and opportunities barely imaginable a generation before. Its security has been enhanced as an influential player in a club of friendly nations. These achievements are now at risk because of the Law and Justice government’s almost fanatical drive to hobble Poland’s judiciary, in clear breach of the constitution and now in contravention of its EU obligations.

Poland’s constitutional tribunal last week ruled that Warsaw does not have to comply with orders from the European Court of Justice related to its judiciary. The orders in this case are ECJ instructions to Warsaw to suspend immediately the operations of a special chamber it set up last year to discipline judges. The chamber is one of several steps the Polish government has taken in a campaign to bring judges it regards as disloyal to heel. As it happens, the following day the European court ruled the disciplinary chamber could be used as an instrument of political control. It was the third time the ECJ has condemned the Polish government for its attacks on judicial independence.

With its judgment, the Polish tribunal has on judicial issues rejected the primacy of EU law over national law, the legal glue that holds the EU together. It is true that other constitutional courts have also challenged the supremacy of EU law. France’s Conseil d’Etat partly did so earlier this year. The German constitutional court last year ruled that the ECJ had acted beyond its powers when it approved bond purchases by the European Central Bank, even though the ECJ is supposed to have the last word.