Polish Supreme Court judges including the body's chief justice are set for a showdown with the country's right-wing government, as they vowed to defy controversial reforms forcing their retirement.
Demonstrations in support of the defiant judges were scheduled for today and tomorrow around the Supreme Court offices in Warsaw.
Backing their stance, the European Union yesterday launched legal action against Poland over the Supreme Court reforms that critics have decried as unconstitutional.
The European Commission said a move to reduce the age at which Supreme Court judges must retire from 70 to 65 would undermine judicial independence, breaching Poland's obligations under EU law.
The new retirement age, introduced by Poland's Law and Justice (PiS) government, comes into force today and would require more than a third of current Supreme Court judges to step down.
Poland's President Andrzej Duda will formally retire Supreme Court Justice Malgorzata Gersdorf today, presidential aide Anna Surowka-Pasek said yesterday.
But Supreme Court spokesman Michal Laskowski has said that "she intends to remain in her post until 30 April 2020, in line with the provisions of the Polish Constitution".
Supreme Court justices last Thursday endorsed Ms Gersdorf's right to keep her post.
They also said that any Supreme Court justice who took up their duties before the day the new reform comes into force "should remain in their post until the age of 70, without meeting any additional conditions".
Announcing the legal measures against Poland, European Commission spokesman Margaritis Schinas told reporters in Brussels yesterday that swift action was needed to "avoid irreparable damage to the independence of the Supreme Court".
In a separate statement, the commission said it took the view "that these measures undermine the principle of judicial independence, including the irremovability of judges".
Poland has a month to respond to the commission's formal announcement, the first stage of a procedure that could end up in the European Court of Justice.
However, the PiS government is refusing to back down, insisting that the changes are needed to combat corruption and overhaul a judicial system still haunted by the communist era.
Deputy foreign minister Konrad Szymanski said his government would respond "in detail" within 30 days and warned the ECJ would face a "very difficult task".
"Its decision will be very important for the EU because it will define the extent to which EU law can interfere in the autonomy of member states in the way they organise their judicial systems," Mr Szymanski said.
"All member states will follow (this case) with a lot of attention because we will be moving into unknown territory."
The row over the Supreme Court comes as the EU launched hearings last week focused on Poland's alleged violation of judicial independence.
European Commission vice president Frans Timmermans has been leading discussions with Warsaw to try to find a solution to the dispute but has said they had not made any progress.
In December, the EU triggered so-called article seven proceedings against Poland over "systemic threats" to the rule of law, which could eventually see its EU voting rights suspended.
