The European Union's executive issued a formal objection Wednesday to controversial judicial reforms in Poland, ratcheting up pressure in an unprecedented inquiry into whether Warsaw is violating the bloc's fundamental values.
The changes to Poland's Constitutional Tribunal - the country's top court - were introduced by the new conservative government that took power in November. Brussels fears that the reforms are in breach of EU-wide standards on the rule of law.
Since January, the European Commission has been in talks with the Polish authorities aimed at resolving the standoff.
"Despite our best efforts, until now we have not been able yet to find solutions to the main issues at stake," commission Vice President Frans Timmermans said.
The decision to issue a formal statement of objections - outlining the commission's concerns and suggesting remedies - takes the inquiry a step further.
As a last resort, it could lead to a suspension of Poland's voting rights within the EU, but Timmermans - who has been leading the talks with Warsaw - said it was too early to discuss what might happen next.
"I don’t want to speculate about future steps," he said. "I still see us in a process of dialogue, of constructive dialogue. We haven't reached the end of that yet."
Polish Prime Minister Beata Szydlo reacted coolly to the move.
"An opinion is an opinion," she said. "That has no influence whatsoever on decisions that are taken in Poland."
Wednesday's announcement marks a U-turn after the commission backed off from escalating its inquiry last week, noting that this was an internal matter to be resolved in Poland.
Polish Justice Minister Zbigniew Ziobro expressed surprise at the decision.
"Mr Timmermans and his closest employees know very well that the government showed great elasticity and the will to find a compromise," he said.
The row between Warsaw and the EU revolves around changes to the 15-judge Constitutional Tribunal including a new two-thirds majority for verdicts to take effect and a rule that requires the court to take cases in the order in which they were filed.
The Polish government and the tribunal have been in a standoff for weeks, after the tribunal's judges ruled in March that the changes to the court are unconstitutional. The government refuses to recognize the ruling.
Critics say the new measures are intended to strengthen the grip of the ruling Law and Justice party on the judicial branch.
Ziobro said the tribunal and the opposition had refused to work towards a solution. "A compromise needs two sides," he said.
Timmermans insisted that the commission "does not wish to involve itself in a political debate in Poland." Its business was preserving the rule of law across the EU, he added.
Many officials in Warsaw have accused the commission of overstepping its mark and meddling in internal Polish affairs. The government has argued that the constitutional reforms were necessary to address a political bias against it.
"You do not question our sovereignty and the right to change," the influential leader of Law and Justice, Jaroslaw Kaczynski, had said in an interview on Monday, raising the prospect of taking the issue to the EU's top court.
The Venice Commission, a body of constitutional law experts that is part of the 47-country Council of Europe, has found that the Polish reforms "undermine democracy, human rights and the rule of law."