By Alan Charlish and Pawel Florkiewicz
WARSAW (Reuters) -A top Polish court postponed a ruling on whether the constitution takes precedence over EU treaties on Tuesday, in a case that could bring Warsaw's conflict with Brussels over the rule of law to a head.
The Constitutional Tribunal adjourned proceedings and will resume on Thursday.
Warsaw aims to hit back at what it says is unjustified interference in its internal affairs by the European Commission, but critics say that questioning the primacy of EU law undermines the functioning of the bloc and jeopardises Poland's continued membership.
"The constitution occupies the highest position in the hierarchy of legal acts," Krzysztof Szczucki of the Government Legislation Centre told the court. "It was not possible to delegate to an authority external to the state the competence to issue decisions that undermine the constitution."
Poland is embroiled in a long-running dispute with the EU over judicial reforms which critics say undermine the independence of the judiciary, but which the ruling nationalist Law and Justice (PiS) party says are needed to make courts function more effectively and remove a residue of communist influence.
PiS says the EU is interfering in Poland's right to make its own laws by challenging the reforms, and in March Prime Minister Mateusz Morawiecki asked the Constitutional Tribunal to rule on whether Poland's constitution should take precedence.
"PLAYING WITH FIRE"
The European Commission has asked Poland not to question the primacy of EU law, expressing concern that it is contesting the bloc's fundamental principles.
Human Rights Ombudsman Adam Bodnar, a vocal government critic, warned the court that choosing not to follow EU law could have serious consequences.
"If the Constitutional Tribunal follows this path it will be playing with fire... fire that sooner or later will lead to Poland's removal from the EU," he said.
As part of proceedings initiated by Brussels against Poland, the EU Court of Justice told Warsaw last year to suspend a panel created to discipline judges.
The panel - the Supreme Court's disciplinary chamber - asked the Constitutional Tribunal whether such a suspension was constitutional. The tribunal will rule on this on Wednesday.
Government critics say the Constitutional Tribunal itself has become politicised as a result of PiS's reforms, an accusation the government denies.
The tribunal's head, Julia Przylebska, was described by PiS leader Jaroslaw Kaczynski as a "close friend".
The European Court of Human Rights ruled in May that a Polish company had been denied its right to a proper hearing in the Constitutional Tribunal due to the illegal appointment of a judge.