Judge Aileen Donnelly refused to approve the extradition of Artur Celmer to Poland, where he is wanted on drug trafficking charges, saying the rule of law had been “systematically damaged” by Warsaw’s legislative overhaul.

“The recent changes in Poland have been so damaging to the rule of law that this Court must conclude that the common value of the rule of law” has been breached, Donnelly was quoted as saying by The Irish Times.

Reforms introduced by Poland’s Law and Justice party include giving parliament the power to choose members of the National Council of the Judiciary, whose task is to oversee judicial impartiality.

Another new law ends the mandates of nearly half of Poland’s Supreme Court justices, a move denounced by the country’s Chief Justice Małgorzata Gersdorf as a “coup”.

Citing the situation in Poland, Donnelly referred the extradition case to the European Court of Justice.

Celmer’s lawyer Ciaran Mulholland said it was an “unprecedented European extradition case arising from the erosion of the rule of law in Poland”.

“The operation of the European Arrest Warrant system involving Poland is now seriously jeopardised,” he said, according to The Irish Times.

The European Commission has already launched unprecedented disciplinary proceedings against Warsaw over what it sees as systemic threats to the independence of the Polish judiciary.

The former head of Poland’s constitutional court, Andrzej Rzepliński, told the newspaper that the decision in Dublin was “extremely significant because this is the very first case of this type in the history of the European Union”.

Marcin Warchoł, Poland’s deputy justice minister, rejected the decision in Dublin and said he hoped it would change.

“It is inconceivable that general, abstract considerations, ideas, and speculations are at the heart of such a crucial decision,” he said, in comments run by the PAP news agency.