Poland's top court backed President Andrzej Duda on Wednesday in a dispute with the government over the validity of bills passed without the presence of two convicted lawmakers.

The decision by the Constitutional Tribunal, which rules on the validity of laws but whose independence is questioned by the new government that took power in December, looked likely to deepen chaos in Poland's legal system.

The dispute over the lawmakers is also part of a political battle in which centrist Prime Minister Donald Tusk is trying to reverse changes made by the previous government, including to the Constitutional Tribunal's line-up.

The Tribunal ruled on Wednesday that two minor bills adopted in parliamentary votes in which former Interior Minister Mariusz Kaminski and his deputy, Maciej Wasik, were unable to take part were unconstitutional.

Kaminski and Wasik served in the previous government led by the nationalist Law and Justice (PiS) party.

The parliamentary speaker declared they had lost their seats after they were convicted of abuse of power in December but Duda, a PiS ally, pardoned them in January and said they should be able to sit in parliament.

Duda then sent several bills that had been adopted in votes without their participation to the Tribunal, and asked it to consider whether they were in line with the constitution without Kaminski and Wasik being able to vote.

Tusk's pro-European government questions the legality of the Tribunal in its current line-up and refuses to abide by its rulings.

Since the new government took power, Parliament has started work on reforming the court, but PiS has attempted to block the government's reforms.

Critics of PiS say three of the Tribunal's judges should not have been appointed because they replaced judges already appointed to those positions by parliament.

The European Court of Human Rights ruled in 2022 that some judges' appointments were illegal and denied citizens the "right to a tribunal established by law". Similar reservations were expressed by the European Commission, the EU's executive body.

Since the new government took power, the Commission has unblocked billions of euros in European funds for Poland that were frozen under PiS because of concerns about the rule of law.