Thousands of Poles have participated in demonstrations across Poland to protest moves by the new right-wing government to neutralize the Constitutional Tribunal as a check on its power.

The protesters, among them former anti-communist dissidents, said they fear Poland's 26-year-old democracy is threatened by the government's moves against the court.

The Law and Justice party, which took power last month, controls both houses of parliament and the presidency, leaving the constitutional court as the only effective check on its power.

The party plans to pass new legislation in the coming week which would essentially make the court unable to work. A key provision of the law would require a two-thirds majority by the 15-judge tribunal for any ruling to be valid, something almost impossible to achieve on contentious issues.