FILE PHOTO - The flags of Poland and European Union flutter in front of the Polish parliament in Warsaw June 29, 2011. REUTERS/Kacper Pempel

BRUSSELS (Reuters) - Poland has failed to uphold the independence of its Supreme Court, the advisor to the EU’s top court said on Thursday, arguing that the lowering of judges’ retirement age breaks European Union law.

Poland’s ruling Law and Justice (PiS) party pushed through a range of powers after coming to power in 2015 that rights groups and EU officials said threatened the rule of law and increased the government’s control over Polish courts.

The PiS originally argued the changes were needed to improve the efficiency of the courts and rid the country of a residue of Communism.

As an interim measure, the Court of Justice of the European Union had last December ordered Poland to suspend the law lowering the age of retirement, which the PiS had already agreed to scrap.

However, a final judgment is still pending.

“The court should rule that the provisions of Polish legislation relating to the lowering of the retirement age for supreme court judges are contrary to EU law,” Advocate General Evgeni Tanchev said in a statement.

Tanchev said the measures are “liable to expose the Supreme Court and its judges to external intervention and pressure from the president of the Republic” and they also impair “the objective independence” of the court.

Judges at the Court of Justice of the European Union, Europe’s top court, follow the advice of their advocate generals in the majority of cases although they are not bound to do so.