By Tamim Elyan
CAIRO, Dec 24 (Reuters) - Egyptian judges were on Monday investigating complaints of voting irregularities before declaring the result of a referendum set to show that a controversial new constitution has been approved.
Opponents of the constitution, drawn up mostly by Islamists and fast-tracked to a vote by President Mohamed Morsi, have demanded a full probe into what they say were a litany of irregularities.
A tally by the Muslim Brotherhood, which lifted Morsi into elected office, indicated a 64 percent "yes" vote, although only a third of the 51 million eligible Egyptians took part. An opposition count was similar, but they said the ballot was skewed by abuses in both rounds.
The constitution was intended to draw a line under the era of Hosni Mubarak, the autocrat ousted almost two years ago, and provide the basis for a new, stable, civilian-led democracy.
But the opposition National Salvation Front has said it deepens a rift between the liberals and Islamists who combined to overthrow Mubarak, and will extend the turmoil that has taken a heavy toll on society and economy.
If the "yes" vote is confirmed, a parliamentary election will follow in about two months, setting the stage for Islamists and their opponents, united and rejuvenated by the political crisis, to renew their battle.
"The committee is currently compiling results from the first and second phase and votes from Egyptians abroad, and is investigating complaints," Judge Mahmoud Abu Shousha, a member of the committee, told Reuters.
He said no time had been set for an announcement of the final outcome of but it was unlikely to be on Monday.
The relatively low turnout prompted some independent newspapers to question how much support the charter really had.
"The referendum battle has ended, and the war over the constitution's legitimacy has begun," the newspaper Al-Shorouk wrote in a headline, while a headline in Al-Masry Al-Youm read: "Constitution of the minority."
But the newspaper of the Muslim Brotherhood's Freedom and Justice Party carried a big tick on its front page, with the headline: "The people have commanded: Yes to the constitution."
The party head, Saad al-Katatni, wrote on Facebook that the group's members were "extending our hands to all political parties and all national forces", adding: "We will all start a new page."
But the opposition, made up of liberals, socialists, more moderate Muslims and the Christians who account for one in 10 Egyptians, said they would continue to challenge the charter through protests and other democratic means.
"We do not consider this constitution legitimate," liberal politician Amr Hamzawy said on Sunday, arguing that it violated personal freedoms.
"We will continue to attempt to bring down the constitution peacefully and democratically."
Opponents say the charter favours Islamists and tramples on the rights of women and minorities, notably the large Coptic Christian community.
The run-up to the referendum was marred by protests, originally sparked when Morsi awarded himself broad powers on Nov. 22. At least eight people were killed when rivals clashed in protests outside Morsi's official palace in Cairo, and violence flared in Alexandria on the eve of both voting days.
By forcing the pace on the constitution, he may have squandered the opportunity to build consensus for the austerity measures needed to rein in a crippling budget deficit.
The political crisis has already prompted a delay in a meeting of the International Monetary Fund's board to sign off on a $4.8 billion loan seen as critical to restoring investor confidence. Egypt says the board will meet in January.