PiS supporters gathered in Warsaw on Thursday evening to protest against the ongoing reforms.
Tens of thousands of supporters of the Law and Justice party gathered Thursday evening in the center of Warsaw, the Polish capital.
The conservative nationalists PiS were in power until last month and their supporters are protesting reforms implemented by the new liberal government of Donald Tusk.
The PiS has already demonstrated since its defeat in the October elections but this is the first time that it has mobilized so many people.
Poland is split between support for the old and new governments and crises have erupted in institutions and the media in recent weeks.