Egypt's President Mohamed Morsi called a Dec 15 referendum on a new constitution, hoping to end protests over a decree expanding his powers, as at least 200,000 of his Islamist supporters rallied in Cairo on Saturday.

Approval of the constitution drafted by an assembly stacked with Morsi's Islamist allies will override the Nov 22 decree that temporarily shielded Morsi from judicial oversight and triggered statements of concern from Western governments.

The decree plunged Egypt into its worst crisis since Morsi won office in a June election and sparked countrywide protests and violence in which two people have been killed and hundreds injured. This hit an economy just showing signs of recovery.

The Supreme Constitutional Court, Egypt's top court, said on Sunday it has begun an open-ended strike in what it called a "black day" for the judiciary after Islamist protesters blocked the courthouse ahead of a key ruling.

The court said it would "suspend work for an indefinite period" in a statement carried by the official MENA news agency.

"I renew my call for opening a serious national dialogue over the concerns of the nation, with all honesty and impartiality," Morsi said after receiving the final draft from the constituent assembly. "We must move beyond the period of confrontation and differences, and get on to productive work."

The constitution is meant to be the cornerstone of democracy in the post-Hosni Mubarak era. Yet drafting it has been divisive, exposing splits between newly empowered Islamists and their opponents.

Protesters in an open-ended sit-in in Cairo's Tahrir Square accuse Morsi's Muslim Brotherhood of trying to impose a flawed constitution.

Leading opposition figure Mohamed ElBaradei said on Twitter that "struggle will continue" despite the referendum and that the draft constitution "undermines basic freedoms".

The draft constitution contains Islamist-flavored language that opponents say could be used to whittle away human rights and stifle criticism. It forbids blasphemy and "insults to any person", does not explicitly uphold women's rights and demands respect for "religion, traditions and family values".

The text also limits presidents to two four-year terms, requires parliamentary approval for their choice of prime minister and introduces some civilian oversight of the military - although not enough for critics.

Morsi described it as a constitution that fulfilled the goals of the Jan 25, 2011, revolution. "Let everyone - those who agree and those who disagree - go to the referendum to have their say," he said.

Reuters-AFP