The increasingly bitter row centres around the European Commission’s view changes proposed by the ruling conservative Law and Justice (PiS) party fall short of EU standards when it comes to rule of law.
Brussels chiefs saw the plans also erode the independence of the judiciary.
But a senior Polish diplomat made it clear Warsaw was sticking to its guns despite threats of sanctions from Brussels.
He said: “The government is not certain that the European Commission has the competence to interfere in the Polish judicial system.
“The government doesn’t understand why the Commission is able to be so active in the rule of law framework — the member states and the European Council should be responsible for that.”
The Commission said its main concern was that the law included illegal gender discrimination by introducing different retirement ages for female and male judges.
It also fears the independence of the courts would be undermined by giving the minister of justice “the power to prolong the mandate of judges who have reached retirement age, as well as to dismiss and appoint Court Presidents”.
But Poland’s foreign ministry insists the measures “are in line with European standards” and “respond to many years of growing social expectations in this regard”.
A spokesman said the ministry had provided “exhaustive clarifications” in a letter responding to concerns expressed by the Commission in writing last month.
Poland also said it was “hoping to continue the dialogue on the merits of the case without any political elements” — underlining Warsaw’s contention the criticism it faces is politically motivated.
The letter was Warsaw’s response to a so-called “recommendation” adopted by the Commission last month.
Brussels has warned Warsaw if any Supreme Court judges were forced out of office, it would trigger the EU’s so-called “nuclear option” — the Article 7 procedure that can theoretically lead to a country being stripped of its right to vote in the European Council.
The Commission has also launched infringement proceedings against Poland’s overhaul of the lower courts.
This a step taken by Brussels if it believes a member country has broken EU law and can lead to the Commission taking a government to the European Court of Justice.