CAIRO -- Egypt's highest court Sunday postponed ruling on a case against the constitutional assembly after Islamist supporters of President Mohamed Morsi blocked judges from entering their chambers in an escalating struggle over the nation's political charter.

Protesters rallied in front of the Supreme Constitutional Court, which was expected to rule on the legitimacy of the constitutional assembly in defiance of Morsi's decree that the assembly was not subject to judicial oversight. The case has heightened the political divisions and created a backlash against judges connected to the deposed regime of Hosni Mubarak.

The judges announced the "suspension of court sessions until the time when they can continue their message and rulings without any psychological and material pressures," according to a statement.

The protest against the court was the latest skirmish in a separation-of-powers battle over the constitution. The assembly approved a draft constitution on Friday to preempt a court decision that was expected to be against the assembly. Morsi ordered a referendum on the constitution on Dec. 15, sidelining the court.

Crowds across the country have been protesting Morsi's power grab for more than a week, reviving the revolutionary fervor that brought down Mubarak in February 2011. The opposition says Morsi, who was elected in June, has made a sham of democracy and that the constitution raises the prospect that Islamic law could jeopardize civil rights.