Tens of thousands walked the streets of Warsaw on December 12-13 to protest or support the actions of the Law and Justice (PiS) government, which has provoked a storm of criticism since it took office a month ago.

The demonstrations came in the context of the constitutional crisis that has been rocking Poland since early December. Critics claim PiS is trampling democracy as it performs a crude power grab. PiS claims it needs a friendly constitutional court to make sure its reforms are not blocked, and that the government is simply dismantling traps set by the previous Civic Platform (PO) administration.

Set up in opposition to PiS, the Committee for the Defence of Democracy (KOD) Facebook group organised a march on December 12. A reported 20,000-50,000 - the lower estimate from the police, the other from city hall – walked through the centre of Warsaw, including many prominent opposition politicians.

"Today, it's an assault on the constitutional court, tomorrow, it could be an assault on our freedom," Ryszard Petru, the head of the new pro-market party Modern Poland, told the crowd according to Reuters.

The following day, PiS gathered 17,000-45,000 of its own supporters. "We won the election, but we have no right to set laws and remodel Poland," PiS chairman Jaroslaw Kaczynski told the crowd.

The opposing demonstrations illustrate the dangers of a growing divide in Poland. During the election campaign, PiS skillfully tapped into the reactionary mood reaching across Europe, and the split in Poland between the major cities and a conservative and strongly Catholic electorate mainly based in rural areas.

However, despite bringing thousands onto the streets in protest already, PiS is nonetheless faring well according to polls. The party retains support of around 35%, equal to combined popularity of Modern Poland and PO. That suggests the constitutional spat is of little concern to many voters.