Poland's constitutional court ruled once again on Thursday that the European Convention on Human Rights is partly incompatible with the Polish constitution.
The Constitutional Tribunal, appointed mainly by Poland's nationalist-populist government, took issue with Article 6 of the human rights convention's compatibility with Polish law.
That article guarantees a person's right to a fair trial by an independent and impartial court.
The tribunal denied the European Court of Human Rights (ECHR) and national courts the right to "review the constitutionality and compatibility" of Polish laws on the judiciary with the human rights convention.
The constitutional tribunal had already rejected an ECHR judgment in November that questioned the legality of the appointment of judges to the Constitutional Court.
The ECHR has recently delivered several critical judgements on the controversial reform of Poland's judiciary, which Brussels has also accused of undermining judicial independence.
The Polish government, for its part, says that its reforms are necessary to combat judicial corruption, criticising "interference" from Brussels.
The EU, however, says that the reforms undermine the independence of the judiciary, undermining the rule of law and ultimately democracy.
In a decision that caused a stir in the EU, the Polish constitutional tribunal rejected the primacy of European law over Polish law, sparking a row with Brussels that blocked approval of Warsaw's economic recovery plan.