The European Commission has urged Poland not to adopt a new law, which, it says, could “undermine” the constitutional order.

Frans Timmermans, the commission vice-president, in a letter on Wednesday (23 December) said the bill could see “the integrity, stability, and proper functioning of the national constitutional court undermined.”

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Kaczynski and 'housekeeper' PM Szydlo (Photo: pis.org.pl)

“I would expect that this law is not finally adopted or at least not put into force until all questions regarding the impact … on the independence and the functioning of the Constitutional Tribunal have been fully and properly assessed,” he said.

The letter was leaked the same day by German broadcaster ARD.

Timmermans wrote after Polish MPs, on Tuesday, voted through changes to the tribunal, which, critics say, will help the ruling Law and Justice (PiS) party extend political control.

The law makes it harder for the tribunal to make decisions, by raising the bar from a simple majority to two-thirds, and by raising the quorum from nine out of 15 judges to 13, among other provisions.

It was also voted by the upper house in the early hours of Thursday.

It comes after PiS quashed the nomination of five new judges by the previous government to install its own people.

Timmermans noted that, according to the Polish tribunal’s judgements, three of the five judges should have stayed in place. But PiS is free to change two nominations.

He urged Polish authorities to keep him informed on “the constitutional situation” and to “work closely” with the Venice Commission, an advisory body in the Council of Europe in Strasbourg.

Timmermans addressed his letter to the Polish foreign minister, Witold Waszczykowski, and justice minister, Zbigniew Ziobro.

Both are PiS hawks with little love for EU institutions.

But Waszczykowski, on Thursday, said he has requested a Venice Commission opinion. Ziobro, on Wednesday evening, said he’d be “happy to speak with the [EU] commissioner to clarify the circumstances” of the reforms.

PiS says changes are needed because the tribunal serves the opposition party, Civic Platform.

The PiS chairman, Jaroslaw Kaczynski, has called the judges “a band of cronies.” But his own status is part of the problem.

The party chief de facto controls the PiS president, Andrzej Duda, and PiS prime minister Beata Szydlo.

In a telling sign, TV cameras, during the PiS election campaign, filmed Szydlo buying milk for Kaczynski, a confirmed bachelor, prompting jokes that the PM is his “housekeeper.”

For his part, Luxembourg’s foreign minister Jean Asselborn, whose country chairs the rotating EU presidency, on Wednesday kept up the international criticism.

He told the Reuters news agency the situation “reminds” him of “the path of .. dictatorial regimes.”

He said if PiS weakens the Constitutional Tribunal, it will also weaken the independence of ordinary courts.

“Whoever says that criticism [of Poland] by its European partners is not appropriate doesn't understand Europe,” he said.