The Polish Constitutional Court crisis of 2015 is a political conflict which began in Poland in October 2015 with the appointment of five Constitutional Tribunal judges by the Civic Platform (Platforma Obywatelska, PO) party. These included replacement of two judges whose terms were not due to expire until after the upcoming election that the Civic Platform was predicted to lose. After the Law and Justice (Prawo i Sprawiedliwość, PiS) party won the parliamentary election, it made its own appointments to the court, arguing that the previous appointments of the five judges by PO were unconstitutional. In December, PiS changed the court's decision-making power by prescribing a two-thirds majority vote and mandatory participation of at least 13 of the 15 judges on the Constitutional Tribunal. The appointments and amendments caused domestic protests and counter-protests in late December and early January; one of the most significant outcome was the creation of the Committee for the Defence of Democracy protest movement. The law changes were criticized by the European Union representatives as threatening the rule of law and the human rights of Polish citizens.
On June 25, 2015, the government adopted a new law regarding the constitutional court. It was signed by the president on July 21, 2015. On October 8, 2015 the outgoing Polish Parliament (Sejm), led by Civic Platform as the main party of the governing coalition, elected five new Constitutional Tribunal judges. Three of them replaced judges whose nine-year terms had expired, while two were to replace judges whose terms were due to expire soon after the election. The judges were chosen on the basis of a law passed earlier in the summer, by the PO-controlled Sejm. At the time of the judges' election, opinion polls had shown that the Civic Platform was likely to lose the upcoming Polish parliamentary election on October 25. If the judges appointed by PO had taken their seats on the Tribunal, the result would have been that 14 out of 15 Constitutional Tribunal judges would have been selected by the Civic Platform. However, the President of Poland, Andrzej Duda, refused to swear in these judges stating that they had been chosen "in contravention of democratic principles". On October 25, the Law and Justice (Prawo i Sprawiedliwość, PiS) party won an unprecedented absolute majority of seats in the Polish parliamentary election. On November 16, new Prime Minister Beata Szydło and her Cabinet took power.