Poland has accused the Dutch EU commissioner, Frans Timmermans, of "left-wing" bias and "astonishing" ignorance in trying to “exert pressure” on constitutional reform.

If Timmermans had expected a conciliatory reply, on technical issues, after he asked the Polish justice minister, Zbigniew Ziobro, in December to explain the reforms, then he would have been surprised on Monday evening (11 January).

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Timmermans: Had asked Poland to halt constitutional law, pending clarification (Photo: europarl.europa.eu)

Ziobro said in his letter that he’s “astonished” by Timmermans’ “lack of knowledge about the factual developments”.

“I deplore your … unjustified accusations and unfair conclusions,” he said.

“May I ask you to exercise more restraint in instructing and cautioning the parliament and government of a sovereign and democratic state in the future, despite the ideological differences that may exist between us, with you being of a left-wing persuasion,” he added, referring to Timmermans’ past in the centre-left Labour Party.

The exchange of letters comes after the right-wing Law and Justice (PiS) party, which won the Polish elections in October, hurried through changes to the country’s constitutional tribunal.

It removed five judges nominated during the former, Civic Platform (PO) party-led government and installed its own people.

It also raised the threshold and quorum for the tribunal to issue verdicts, making it harder to vet future legislation.

Ziobro said the changes are needed because the PO, in its term in office, had “tried to monopolise the court” with its loyalists.

He said the PO “hurriedly” appointed five new judges just before the October elections, depriving the new parliament of the chance to do so.

“These disgraceful activities … regrettably failed to attract your attention at that time,” he told Timmermans.

He said PiS’ actions are designed to “reinstate pluralism” in the constiutional tribunal.

He added that the head of the top court, Andrzej Rzeplinski, who is meant to be neutral, openly “declares himself to be a supporter of the Civic Platform” and “acts as a politician” due to his “political ambitions”.

Ziobro’s letter arrived shortly before the commission holds a debate on Poland on Wednesday.

A commission spokesman, Margaritis Schinas, said on Tuesday that Timmermans is “analysing” what Ziobro said, as well as a previous Polish letter on overhaul of state media.

Some commissioners, such as Germany’s Guenther Oettinger, have said Poland should be placed under a supervisory mechanism, which could lead to EU sanctions.

But Schinas hit a softer note, saying Poland has, "exactly as requested by vice-president Timmermans", entered into a dialogue with the Venice Commission, a constitutional advisory body in the Council of Europe in Strasbourg.

For its part, Rzeplisnki’s tribunal will, on Tuesday, issue its own verdict on the legality of the PiS reforms.

It will do so under its old composition and quorum.

But the government has said it won’t recognise its decision or print it in the country’s official gazette.

The situation means that Poland, a country of 40 million people, could, the same day, enter into judicial limbo: It’s top court won’t be able to issue binding verdicts, while refusing to make changes to go back to business as usual.

MEPs will also hold a debate on Poland in Strasbourg next week, with Polish prime minister Beata Szydlo saying on Tuesday that she’ll attend.