Former EU Council President and Polish opposition leader Donald Tusk has called for protests against a controversial ruling by his country's constitutional court.
"I call on everyone who wants to defend a European Poland to come to Palace Square in Warsaw at 6 p.m. on Sunday," he wrote on Twitter on Thursday evening.
“We can only stop them together.” Tusk is the acting chairman of Poland's largest opposition party, the liberal-conservative Civic Platform.
Poland's constitutional court ruled on Thursday that certain elements of EU law violate the Polish constitution.
This gave national law priority over EU law.
This decision met with a negative response in Brussels.
It is fueling the conflict between the EU Commission and Warsaw over the reform of the Polish judicial system.
Poland's government, led by the national conservative party PiS, has been restructuring the judiciary for years.
Critics accuse her of putting judges under pressure.
Because of the reforms, the EU Commission has already opened several infringement proceedings against Warsaw and filed suits with the European Court of Justice.