The head of Poland's Supreme Court Małgorzata Gersdorf is defying a new law that would force her to retire, triggering a further escalation of tension between the European Union and the member state.

The law, which entered into force at midnight Tuesday, mandates that all Supreme Court judges over the age of 65 must retire and would force 27 of the 72 judges off the bench.

Presidential aide Pawel Mucha told state media that Gersdorf’s forced retirement would be “in line with binding laws” and that current judge Józef Iwulski will fill her position.

But Gersdorf claims that the new rules contravene the constitution and and cannot be implemented, Reuters reported. “My situation is defined by the constitution … and that cannot be changed,” she was quoted as saying by the PAP news agency on Tuesday.

The European Union has contested the law, and recently launched an infringement procedure against it. In a statement, the EU said the legislation would “undermine the principle of judicial independence, including the irremovability of judges”.

On Tuesday, the dispute triggered protests in front of the court in Warsaw, which Gersdorf also attended. Hundreds gathered to wave EU flags and placards reading “constitution” to show their support for the supreme court judge.

Since the conservative Law and Justice (PiS) party came to power in 2015, the EU has clashed repeatedly with Prime Minister Mateusz Morawiecki’s government over judicial reforms that have broadened the government’s power over the Supreme Court and national council of the judiciary, which appoints judges.

In December, the EU triggered an unprecedented disciplinary process against Poland for a “serious breach” of its values. The European Commission, the EU’s principal adinistrative body, warned of a “clear risk of a serious breach in the rule of law” posed by the legal reforms and recommended that EU leaders invoke Article 7, a process that could eventually lead to Poland’s voting rights being suspended.

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