Thousands of Poles have rallied in support of the Law and Justice Party (PiJ) government's moves to hire and fire judges.

Gathering in front of the Constitutional Tribunal in the capital Warsaw, some said the changes to laws concering the judiciary were a matter of national sovereignty.

The rally included speakers who described the new legislation as necessary to clean up what they denounced as a corrupt "caste'' of judges that had been in their positions since the communist era.

One of the organisers attacked the European Union, which remains in a prolonged stand-off with Poland over concerns about the erosion of the rule of law.

"What the officials of the European Union do is an abuse of the law, they have no right to interfere with the justice system," Adam Borowski said.

The EU and many Polish judges say the changes violate the separation of powers essential in a democracy.

In a statement on Wednesday the International Commission of Jurists described the changes as "a rapidly escalating rule of law crisis."

Four days ago a new law gave politicians the power to fine and fire judges whose actions and decisions they consider harmful.

That law comes after more than four years of reforms to the judicial system by the PiJ.