* Supreme Judicial Council to oversee vote, says Mursi adviser
* Any boycott by judges threatens plebiscite's credibility
* Mursi sees constitutional referendum as way out of crisis
By Tom Perry and Marwa Awad
CAIRO, Dec 3 (Reuters) - Egypt's Supreme Judicial Council has cleared the way for a referendum on a new constitution which President Mohamed Mursi hopes will end a political crisis that has split the country.
Some judges had called for their colleagues to shun the Dec. 15 plebiscite, which must be supervised by the judiciary like all elections in Egypt. But the council's decision suggests enough officials can be mobilised to oversee the vote.
"The Supreme Judicial Council has met and agreed to delegate judges to oversee the constitutional referendum," Mohamed Gadallah, a legal adviser to Mursi, told Reuters on Monday. State media also reported the decision of the council.
Gadallah said about 10,000 members of the judiciary are needed for the monitoring. These do not all have to be judges and could include officials in prosecutors' offices for example.
"This moves Mursi closer to credible judicial supervision of the referendum but probably will do little to reassure his opponents of the legitimacy of the process, beginning from the formation of the constitutional assembly," said Elijah Zarwan, a fellow with the European Council on Foreign Relations.
Judicial dissent has complicated the Islamist leader's effort to end the crisis over Egypt's political transition by driving through a new constitution in a snap vote in a drafting assembly dominated by his Islamist supporters.
The influential but unofficial Judges Club had called on Sunday for a boycott of the referendum which Mursi hopes will douse anger over a decree he issued on Nov. 22, expanding his powers and temporarily putting himself above judicial review.
Such a boycott, even if not all judges joined it, could undermine the credibility of the plebiscite and worsen disputes that have plagued Egypt's path to political change since a popular revolt overthrew Hosni Mubarak nearly 22 months ago.
The judiciary, like Egyptian society at large, is split over the vote on the constitution, the way in which it was drafted and Mursi's decree, seen by his opponents as a power grab and by his supporters as necessary to keep the transition on track.
There was no direct comment from the judicial council, the body which formally oversees judicial affairs.
Many judges voiced outrage at Mursi's decree, which caused unrest in which three people were killed and hundreds wounded. Even his justice minister and vice president - brothers who were formerly respected judges who advocated judicial independence in Mubarak's time - have expressed misgivings.
The opposition has called for another mass protest on Tuesday in Cairo's Tahrir Square, the cradle of the anti-Mubarak revolt. Mursi's opponents have camped out there since Nov. 23. Some activists plan to march to the president's office.
Several independent newspapers will not publish on Tuesday in protest at what they call Mursi's "dictatorship".
The constitution, which if approved would override the decree, is itself contested by opposition groups who say the Muslim Brotherhood hijacked the drafting of a document they say has no legitimacy in a deeply polarised society.
"Settling this matter using the ballot box is an illegitimate trick representing false democracy," liberal opposition leader Mohamed ElBaradei said on Twitter.
The Judges Club boycott call carries echoes of Mubarak's days, when independent-minded sections of the judiciary refused to oversee elections unless he enacted judicial reform.
However,, one leading figure in that campaign for judicial independence, former Judges Club head Zakaria Abdel Aziz, said the judges had a "national duty" to oversee this referendum.
"A lot of judges called me and they are heading in the direction of supervising the referendum," he told Reuters.
"The head of the Judges Club is pushing in the direction of scorched earth," he said. "He and some of those that support him have pulled the judges into a political battleground."
Ahmed el-Zind, who now heads the Judges Club, has staunchly opposed Mursi's decree, taking the side of the former prosecutor general, a Mubarak-era appointee sacked under its provisions.
"We will not supervise a referendum that slaughters the nation's rights," Zind told Al-Masry Al-Youm newspaper on Monday. Zind's critics say his enthusiasm for an independent judiciary only became apparent after Mursi took office.
The Judges Club recommendation for a referendum boycott by judges is not binding. Its earlier call for a judicial strike against Mursi's decree saw partial success, with the Cassation Court and Egypt's highest appeals court ceasing work.
On Sunday, the Supreme Constitutional Court, the highest in the land, followed suit, complaining that Mursi supporters outside its headquarters were intimidating the judges.
The court had been due to hear cases contesting the legality of parliament's Islamist-led upper house and of the assembly that wrote the constitution, which was handed to Mursi on Saturday.