Poland’s judiciary reform that lowered the retirement age for Supreme Court judges has breached EU law, the EU’s top court said in a binding ruling on Monday, which effectively means Poland will have to scrap the reform or face penalties from Brussels.

The court case is the second launched by the European Commission against Warsaw over of its rule of law infringement procedure since the Law and Justice (PiS)-led government launched an overhaul of the Polish legal system in 2016.

With the law in question, Warsaw has lowered the retirement age for judges at the common court and Supreme Court, as well as prosecutors, to 60 for women and 65 for men.

The European Commission accused the government in Warsaw of curtailing the independence of the judiciary and undermining the separation of powers.

Opponents of the law believe the reforms are ultimately intended to stack Polish courts with pro-government supporters and have called them a political “purge.”

The Polish government insists the changes are needed to tackle corruption and clean up a judicial system still haunted by the communist era legacy.

Last year, Poland backed down and allowed the return of the Supreme Court judges who had to retire. However, the EU side has viewed the changes not to be sufficient enough as the law remained in force.

In a non-binding opinion that preceded the court’s ruling, Evgeni Tanchev, Advocate General at the European Court of Justice (ECJ), called on Thursday the new rules “contrary to EU law” and advised the court to rule against Warsaw.

Tanchev also said the lowering of the retirement age of judges “must be accompanied by protective measures” to ensure that a judge is not de facto dismissed.

The adviser added that despite small amendments to the law made last year, “these changes have not managed to solve all of the issues” raised by the commission, the EU’s executive arm.

In Monday’s ruling, the court said that the measures breach EU rules as the freedom of the judges from all external intervention or pressure is essential and that judges’ terms could only be shortened in exceptional circumstances.

“The Polish legislation concerning the lowering of the retirement age of judges of the Supreme Court is contrary to EU law,” the court reasoned in its binding ruling.

The Polish judicial overhaul “is not justified by a legitimate objective” and “undermines the principle of the irremovability of judges, which is essential to their independence,” the court reasoned.

“The implementation of a new mechanism allowing the president . . . to decide, on a discretionary basis, to extend the . . . period during which a judge carries out his or her duties and the fact that the measure in question affected almost a third of the serving members of that court, including its First President, whose 6-year mandate guaranteed under the Constitution was shortened, are such as to raise serious doubts as to the real aims of that reform,” the court said.

It also said that lowering the retirement age for Supreme Court judges was “not justified by a legitimate objective and undermines the principle of the irremovability of judges”.

There has been no immediate reaction from the government in Warsaw.

Human rights groups such as Amnesty International have welcomed the ruling, calling it significant for Poland and other EU member states “who think they can breach human rights with impunity.”

“Deciding otherwise would have undermined the credibility of Article 2 [of the Treaty of the European Union] values to an impermissible debate and, crucially for the Court, would make it impossible for the local judges in the member states to fulfil their core EU functions as European judges,” Dimitry Kochenov, a professor of EU constitutional law at the University of Groningen, told EURACTIV after the ruling.

“It is absolutely clear that the Court and the Commission have successfully learnt from the mistakes committed in an essentially similar Commission v Hungary case.”

According to Kochenov, the judicial overhaul in Poland will slow down as laws produced will now have no legal effect as far as the Supreme Court is concerned.

Warsaw has now the choice either to roll back its judiciary reforms and comply with the ruling or risk further action from the European Commission, which could involve financial penalties.

Legal experts, however, point out that the decision only questions the Polish laws as far as the pensionable age — it does not annul the reform as such — and more cases are likely to attach other elements of the so called reform.