WARSAW, Poland (AP) — The European Union has increased its criticism of the Polish government on its rule of law principles and has issued more recommendations for Warsaw to fix its problems.

EU Vice-President Frans Timmermans said Wednesday that the 28-nation bloc "will not drop this matter" until the Polish government addresses questions about the independence of its judiciary and other issues perceived as backsliding on fundamental political rights.

The new EU warnings came as a bitter political standoff in Poland hardened, with opposition politicians vowing to continue a sit-in inside parliament through the upcoming Christmas and New Year holidays.

At the heart of the matter is whether the populist and nationalist Law and Justice party is taking an authoritarian turn and eroding democratic institutions.