Cairo, Egypt ? The government warned on Tuesday that it would not tolerate election day protests, and the opposition fretted about possible ruling party dirty tricks in Egypt’s first contested presidential vote.

President Hosni Mubarak, who has led Egypt for 24 years and is certain to win today’s balloting, calls the election a major step toward greater democracy in a country that has seen only authoritarian rule for more than a half century.

But many Egyptians are skeptical, and the opposition says the vote will do nothing to diminish Mubarak’s power.

Hours before voting started, Prime Minister Ahmed Nazif took a tough line, warning that demonstrations were banned for election day.

The reformist group Kifaya had called for a rally today in one of Cairo’s main squares to protest “corruption and oppression” and the continuation of Mubarak’s rule.

“If there are demonstrations, they will be sabotaging the elections,” Nazif told reporters. “It’s the responsibility of the police and the security forces to secure the voters’ rights to cast ballots.”

George Ishaq, one of the founders of Kifaya, vowed that the group – whose name means “Enough” – would go ahead with the protest.

An Egyptian traffic soldier gestures in front of a poster promoting President Hosni Mubarak, leader of the ruling National Democratic party, in Cairo, Egypt, Tuesday, a day before 10 candidates run in the country's first ever multi-candidate presidential elections, including veteran President Hosni Mubarak.

“We have taken the right to demonstrate, and we are not waiting for anybody to give us permission,” he said. “All I can say is that the whole world will be watching.”

Some 32.5 million Egyptians were registered to cast ballots today. The election commission said counting could take up to three days and final results would not come until Saturday.

Until now, the 77-year-old Mubarak has been re-elected in referendums in which he was the only candidate and voters’ only option was saying “yes” or “no” to his continuing in power.

Mubarak has touted his decision to allow election challengers as a major reform and has promised further democratic steps if re-elected to a fifth six-year term.