Egypt's highest court Tuesday ruled against a decision by President Mohammed Morsi to reinstate the country's dissolved lower house of parliament, DPA reported.
The official ruling by the Supreme Constitutional Court came hours after the assembly convened for a short session, in response to a Sunday directive by President Mohammed Morsi.
Senior judges had already, on Monday, insisted that Morsi's actions were illegal. However, that statement was not the official ruling.
The most recent decision orders the implementation of the court's June ruling, which invalidated the electoral law upon which the parliamentary elections had been based. That, accordingly, dissolved the assembly.
The decision angered thousands of Brotherhood loyalists gathered in central Cairo's iconic Tahrir Square.
Protesters were shouting slogans against Ahmed al-Zend, the head of the Judges' Club, a judicial union, who had attacked Morsi and his decree reinstating the People's Assembly.
The Brotherhood protesters were carrying flags and banners with Morsi's picture on them
The decision is also expected to fuel tensions between Morsi, the judge's union and the Supreme Council of the Armed Forces (SCAF), which ruled the country for a year and a half after Hosny Mubarak was ousted from power in a popular revolt last year.
A presidential spokesman said Morsi was not expected to comment Tuesday evening.
The brief convention of the People's Assembly earlier on Tuesday is widely seen as an attempt by Morsi's Muslim Brotherhood to stake its claim to power.
Parliamentary speaker Saad al-Katatni said lawmakers did not object to the Constitutional Court ruling, but wanted to seek a legal opinion from another court constitutionally tasked with determining the validity of membership in parliament.
The assembly voted on a show of hands to refer the question to the Court of Cassation, following which al-Katatni closed the session.
Many liberal and left-wing lawmakers, including members of the Wafd, Free Egyptians and Social Democratic parties, boycotted the meeting.
Morsi's decree recalling parliament set the stage for a showdown between the military and the Muslim Brotherhood, the organization that was banned under the old regime and which emerged as the largest political force after last year's revolution.
"We are confident that all state institutions will respect all constitutional declarations," the military said in a statement.
The military council granted itself legislative powers in a constitutional declaration after the court first dissolved parliament, raising fears that it was trying to hold on to power.
Leading dissident Mohamed ElBaradei called for an urgent meeting between Morsi, judges and the military council, saying that the "conscience of the nation" demanded "a political and legal solution to avoid an explosion in the country."
Islamists, including the Muslim Brotherhood, hold more than two-thirds of seats in parliament.
Legal experts have been split over whether Morsi had the authority to reinstate the legislature.
Court overrules Morsi's decision to reinstate parliament
Egypt's highest court Tuesday ruled against a decision by President Mohammed Morsi to reinstate the country's dissolved lower house of parliament.