This is the third case filed by the Commission against Poland to the CJEU | Julien Warnand/EFE via EPA EU launches another infringement case against Poland The Commission worries that the government is undermining judicial independence.

WARSAW — The European Commission on Thursday referred Poland to the EU's top court over a new system for disciplining judges.

The move comes just before the October 13 parliamentary election, and marks yet another effort by Brussels to rein in the nationalist Law and Justice (PiS) party government's bid to bring the judicial system under tighter political control.

The Commission launched the infringement procedure on April 3, saying it was concerned that "the new disciplinary regime undermines the judicial independence of Polish judges and does not ensure the necessary guarantees to protect judges from political control."

The new law allows judges to be censured based on the content of their verdicts, as well as punishing them for turning to the Court of Justice of the European Union to request preliminary rulings. The procedures are to be conducted by a disciplinary chamber made up of judges chosen by the National Council of the Judiciary, a body picked by the parliament in which PiS has an absolute majority.

The minister of justice, Zbigniew Ziobro, who is also the chief prosecutor, has enormous influence over the disciplinary procedures.

The Commission addressed its worries to Warsaw, but said that the Polish government's explanations "did not alleviate the legal concerns."

This is the third case filed by the Commission against Poland to the CJEU. It also referred a law forcing Supreme Court judges into early retirement (the EU court found it was illegal) and another one on retirement provisions for ordinary judges.

The Commission has also launched an Article 7 procedure against Poland over concerns that it is violating the EU's democratic standards.

The Polish government insists it is simply cleaning out judges with ties to the communist regime that ended in 1989 and making the judicial system more efficient.

The tensions between Brussels and Warsaw are unlikely to subside if PiS remains in power after Sunday's vote.

Jarosław Kaczyński, the leader of PiS and Poland's de facto ruler, admitted earlier this week in an interview with Polsat television that there had been "difficulties" in pushing through legal reforms, although he insisted that the government hadn't violated the Polish constitution. He promised even deeper changes to the legal system in the future.

"If society trusts us, we will return to this," he said, adding, "Repairing the country is difficult without a deep reform of the courts, because they are in a way the final barricade, the last decision-making level in many issues — civil, criminal and administrative."