WARSAW, Poland (AP) — Poland’s constitutional court is to rule Thursday in a key case over whether Polish or European Union law has primacy in the EU member country.

The ruling by the Constitutional Tribunal is expected to define the future of Poland’s already troubled relationship with the 27-member bloc in the key area of law and justice.

The expected verdict comes after months of court proceedings in which representatives of the government, the president and the parliament argued that Poland's Constitution comes before EU law and that rulings by the Court of Justice of the EU are sometimes in conflict with Poland's legal order.

The court opened the case in July on a motion earlier this year from Polish Prime Minister Mateusz Morawiecki. He asked for the review after the EU court ruled that the bloc's law takes precedence over Poland’s law. The verdict regarded the procedure of judicial appointments under Poland's current right-wing government.

The EU court’s decision came amid a larger dispute over deep changes the governing Law and Justice party initiated to the Polish court system; the EU views the changes as an erosion of democratic checks and balances.

The Constitutional Tribunal itself is seen by the EU as illegitimate due to the political influence of Poland’s governing party on the appointment of some of its judges. Many of them are government loyalists — including the court’s president, Judge Julia Przylebska, who is heading the panel in the current case.

Poland’s government insists that the justice system and the judiciary are the sole purview of EU member nations and not the EU.