The EU’s top court has ordered Poland to “immediately suspend” the application of its law which lowers the retirement age of Supreme Court judges.
The European Court of Justice upheld the request by the European Commission. The Polish government has been accused of trying to appoint loyal judges.
But Warsaw says the reforms, which lower the retirement age from 70 to 65, make the courts more efficient.
Poland has clashed with EU bodies in recent months over a number of issues.
What did the ECJ ruling say?
The Luxembourg-based court ordered Poland to immediately reinstate the Supreme Court judges who have been forced to retire since the new law came into force in July.
About a third of the judges have stepped down, but Chief Justice Malgorzata Gersdorf – who is also affected by the changes – is refusing to quit, saying the Polish Constitution guarantees her a six-year term.
The ECJ said its decision is an interim measure, and a final ruling would be issued at a later date.
Fines could be imposed if Poland is found in breach of EU law.
How did the Polish government react?
Prime Minister Mateusz Morawiecki said the government had during “the last few hours received the court of justice decision”, news agency AFP reports.
“We will certainly respond to it. We will see what these (EU) institutions are proposing. When we take them into consideration, several possibilities will be analysed,” he added.
The judicial reforms triggered mass street protests across Poland.
Opponents say the governing Law and Justice (PiS) party will use the law to appoint new judges loyal to the authorities.
The conservative government denies the accusations, saying the country’s judiciary was not properly reformed after the end of communism in 1989.
Poland and the EU’s tug-of-war
By the BBC’s Adam Easton in Warsaw
The European Commission was so alarmed about the law’s damage to Poland’s judicial independence that it asked the court to impose interim measures before the case has even been heard.
The court agreed, saying its order applied retroactively, meaning all the Supreme Court judges forced into early retirement in July will have to be reinstated.
It’s far from clear how Poland’s governing camp will react.
It has previously ignored a similar interim order from the ECJ to stop logging in the primeval Bialowieza forest.
It only complied when the Luxembourg court issued a second order that imposed daily fines if the logging continued.
President Andrzej Duda, a former Law and Justice MP and ally, has appointed 27 new judges to the Supreme Court.
However, they will mostly fill positions in two newly created Supreme Court chambers, rather than replace the retired judges, which could make it simpler to reinstate the latter.