WARSAW (Reuters) - Poland faced the specter of institutional turmoil and an escalation of tensions with the European Union on Wednesday, with the head of the Supreme Court refusing to comply with reforms that force her to retire.

Polish Supreme Court Chief Malgorzata Gersdorf looks on as people protest against the conservative government's makeover of the judiciary in Warsaw, Poland July 3, 2018. Agencja Gazeta/Dawid Zuchowicz via REUTERS

The reforms go into effect at midnight. Supreme Court officials said chief judge Malgorzata Gersdorf planned to arrive for work at 8.30 a.m. on Wednesday (0630 GMT) and would be welcomed at the court’s entrance by other judges.

Warsaw’s conservative Law and Justice (PiS) government says the reform of the Supreme Court requires Gersdorf to end her term, but the judge says the new rules contravene the constitution and cannot be implemented.

“My situation is defined by the constitution ... and that cannot be changed,” she was quoted as saying by the PAP news agency on Tuesday.

Under the new rules, the 65-year-old judge should have asked President Andrzej Duda for an extension of her mandate if she was to be of retirement age on July 4. She has not done so.

“That would mean subordination,” Gersdorf said. “And I cannot agree to this because I need to fulfill what I swore I would.”

Opponents of the reforms planned demonstrations on Wednesday. Among them is Lech Walesa, the Nobel Peace Prize Laureate and former president who is credited with bringing down communism as Solidarity trade union chief.

The row is a culmination of a broad overhaul of the judiciary implemented by the nationalist ruling party that has fueled unprecedented tensions between the Polish government and the EU over democratic values.

“INTERNAL MATTER”

Through legislation and personnel changes, PiS has taken de facto control of the judicial system since coming into power in 2015, including the constitutional tribunal and prosecutors, who now report directly to the justice minister.

The party argues this is needed to address ineffectiveness in a system steeped in communist-era mentality and power structures.

Critics at home and abroad accuse PiS of seeking control over courts for political gain, and say its policies, which also include tighter control of public media, amount to a shift towards authoritarian rule.

The conflict has isolated Poland within the EU, where most governments are critical, while also exposing the bloc’s inability to rein in governments it believes contradict core EU values.

The European Commission opened a fresh legal case against Poland over the Supreme Court changes on Monday, saying that they undermine judicial independence in the largest formerly communist member of the EU. [nL8N1TY2SQ]

Warsaw faces the threat of losing its voting rights in the bloc under a procedure launched late last year over judiciary reforms. Hungary, also facing criticism over democratic standards, has pledged to block such a move.

The euroskeptic PiS government rejects criticism, saying EU treaties do not give Brussels institutions the power to influence national matters such as the judiciary.

“Let me mention a fundamental issue. The court system ... is an entirely internal matter,” PiS leader Jaroslaw Kaczynski was quoted by the PAP news agency on Tuesday as telling Gazeta Polska newspaper.

The party’s standing in polls has held steady at around 40 percent throughout the dispute, well above any single rival party.