Egypt's Supreme Constitutional Court has frozen the decree issued by President Mohamed Morsi reinstating the Islamist-led parliament.
"The court ruled to halt the president's decision to recall the parliament," Judge Maher el-Beheiry said in court on Tuesday.
Morsi, a former member of the powerful Muslim Brotherhood, ordered on Sunday for the lower house to reconvene, just eight days after taking office.
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Tuesday's ruling came hours after the 508-seat chamber held a brief session, following the president's request for the legislators to convene.
They voted to seek further judicial opinions on the court's decision that had invalidated one-third of the lawmakers because of voting irregularities.
President Morsi's move highlighted the power struggle between the presidency and the Supreme Constitutional Court, which last month said certain articles in the law governing the parliament elections were invalid, annulling the lower house.
Sherine Tadros reports from Cairo
News of the verdict was greeted with chants of "batel", or illegitimate, by thousands of Morsi supporters gathered in Cairo's Tahrir Square.
"Everything now depends on the reaction by parliament," said Al Jazeera's Sherine Tadros, reporting from Cairo.
"The Supreme Court has once again reiterated that the parliament is dissolved," our correspondent said. "It's the third decsion by them saying that Morsi's decison to reinstate the parliament was illegal. They cannot say it in any more certain terms than that."
"They're saying that the parliament sessions cannot continue, which would mean legislative powers would stay in the hands of the armed forces - in this power struggle between the military and the president."