CAIRO: A divided Egypt is being called to vote in a referendum on Saturday on a new constitution that the secular opposition fears will be used by President Mohamed Morsi and his Muslim Brotherhood to usher in Islamist interpretation of laws.

The protests over the draft charter and Morsi’s near-absolute powers that he gave himself for two weeks to push it through, have failed to sway the president from his path.

The country's powerful army, which ruled for 16 months following the ouster of president Hosni Mubarak early last year, has tried in vain to bring both sides together for talks to calm the crisis.

Fears of violence remain after violent clashes in Cairo last week in which eight people were killed and more than 600 injured.

Morsi has ordered the referendum to be split over two consecutive Saturdays because many judges are refusing to monitor voting.

The opposition National Salvation Front on Wednesday said it was urging its supporters to vote “no” – but also said it could call a last-minute boycott if the referendum was not brought back to just one day of voting, and if judges and independent observers did not monitor every polling station.

Mohamed ElBaradei, a former UN nuclear energy agency chief who heads the Front, tweeted: “Insistence on referendum in an explosive, polarised, chaotic & lawless environment is leading country to the brink.”

Both sides have taken started encouraging supporters to back or reject the referendum.

“It's you who will pay the price if you vote yes. No to the constitution,” said an online campaign advertisement by an opposition group called Apr 6.

The pro-referendum camp has released videos with a song that goes “This constitution is not too bad, it was written by a committee of heroes.” It also has supporters holding “Yes to the constitution” placards along main roads.

According to an interior ministry official, 130,000 police officers will be deployed, along with troops, to ensure security during the vote.

Morsi has ordered the army to secure state institutions, giving it powers of arrest until the referendum result is known.

Egyptian citizens were divided over the referendum.

“I'm voting yes,” said Mohammed Hassan, a 28-year-old Cairo resident. “The Muslim Brotherhood is good. No one has given them a chance. They've been in power for five months compared to 30 years for Mubarak,” he said.

Mohammed Ibrahim Sayyid, in his 40s and sipping coffee in a cafe, felt differently. “We don't like what's happening. We don't want another Afghanistan because of the Muslim Brotherhood. We are a big, diverse country of 80 million people. There shouldn't be one party ruling,” he said.

Hamdi Imam, a street bookseller in his 50s, said: “I'm not going to vote because the constitution has blood on it. The Muslim Brotherhood will destroy the country.”

The referendum outcome was uncertain, though many analysts thought it likely to pass, given the Brotherhood's efficiency in mobilising Egypt's vast poorer segment of society.

The opposition sees the proposed charter, drafted by a panel dominated by Islamists, as weakening human and gender rights, bolstering the military and undermining the judiciary's independence.

It fears ambiguities and loopholes in the charter will push Egypt closer to a form of Shariat law favoured by the more ultra-orthodox Islamists.

The UN human rights chief, the United States, European nations and international watchdogs have also criticised the draft constitution and the way it was rammed through.

Saturday will see voters in 10 governorates called to polling stations, including in the two biggest cities of Cairo and Alexandria.

On Dec 22, it will be the turn of Giza, Port Said, Luxor and 14 other regions.

Egyptians abroad have already started early voting in embassies and consulates, the official MENA news agency reported.