The outgoing president of Poland’s highest constitutional court has warned that the country’s ruling rightwing Law and Justice party (PiS) is making a systematic attempt to destroy oversight of government activity. He described the country as being “on the road to autocracy”.

As reported by the Guardian, the departure of Andrzej Rzepliński, whose term expired on December 18, is expected to pave the way for PiS appointees to assume control of Poland’s most important institutional check on executive power.

The expiration of Rzepliński’s term comes amid signs of the most serious political crisis in Poland since PiS won presidential and parliamentary elections in 2015.

On December 16, a group of demonstrators attempted to barricade MPs in the parliament building after the government sought to restrict media access to parliamentary proceedings.

Opposition MPs accuse PiS deputies of holding illegal votes outside the parliamentary chamber after an opposition MP was expelled for protesting against the media restrictions and opposition leaders occupied the parliamentary podium in protest.

Speaking to the Guardian, Rzepliński defended his attempts to uphold the independence of the tribunal, which rules on the constitutionality of legislation and decisions taken by state authorities.

He said the government’s refusal to recognise the legitimacy of a number of the court’s rulings threatened to “create a double legal system, with some courts upholding our rulings, and others not. Judges really don’t know what the law is, and without that, in a continental system, courts cannot operate.”

Meanwhile, Julia Przyłębska is tipped by some observers to be appointed as Rzepliński’s successor.