By Yasmine Saleh and Dina Zayed
CAIRO (Reuters) - Three top contenders for Egypt's presidency were scrambling to stay in the election race on Sunday after the authorities disqualified them on technical grounds, prompting one to say that a "major crisis" threatened the landmark vote.
The election is seen as the last step to democracy after more than a year of unstable army rule since Hosni Mubarak was overthrown by a street revolt. The generals are due to hand power to the new president by July 1 but the latest drama saw new accusations they were trying to prolong their influence.
Mubarak's former spy chief Omar Suleiman drew an outcry from opponents of the old regime when he entered the race last week, only to be told late on Saturday that he had failed to secure enough signatures in one province to run.
Two leading Islamist candidates were also disqualified, one because he has a criminal record - dating from what was widely seen as a political trial under Mubarak - and the other because his mother had taken U.S. citizenship, state media said.
All three have 48 hours to appeal to the state election committee against their exclusion. If their elimination is confirmed, it would redraw the electoral map just weeks before the vote gets under way in May.
"We will not give up our right to enter the presidential race," said Murad Muhammed Ali, campaign manager for the Muslim Brotherhood's Khairat al-Shater, one of the three.
"There is an attempt by the old Mubarak regime to hijack the last stage of this transitional period and reproduce the old system of governance."
The disqualifications add to the drama of a transition marked by spasms of violence and bitter political rivalries between Islamists, secular-minded reformists and remnants of the Mubarak order.
Shater, who became an immediate frontrunner after joining the election race in late March, was disqualified due to past criminal convictions. Brotherhood members were often jailed for their political activities under Mubarak, who excluded the movement from formal politics.
Anticipating Shater's disqualification, the Brotherhood, which now dominates parliament following free elections held in the wake of Mubarak's removal, had nominated Mohamed Mursi, head of its political party, as a reserve candidate.
A lawyer for Salafi preacher Hazem Salah Abu Ismail, the most hardline of the various Islamists running for the post, said there would be a "a major crisis" now that his client was barred from the race.
On Friday, his supporters besieged the headquarters of the election commission, forcing it to evacuate the premises and suspend its work. Abu Ismail said the accusation that his mother held U.S. citizenship was fabricated by his political opponents.
"The presidential committee has violated all the rules of law," Abu Ismail said in remarks published on his Facebook page. "If the official decision is to violate the constitution, they should be able to deal with the consequences."
Military police and state security were guarding the headquarters of the election committee in Cairo on Sunday, state media reported.
Farouk Sultan, head of the presidential election commission, told Reuters a total of 10 of the 23 candidates had been disqualified.
Frontrunners still in the race include Amr Moussa, a former Arab League Secretary General and Egyptian foreign minister, and Abdul Moneim Abol Fotouh, who was expelled from the Brotherhood last year when he mounted his own presidential campaign.
In an interview with Reuters on Saturday, before his exclusion was announced, Suleiman said the domination of politics by the Brotherhood would hold the country back. But he said if he became president, the party could serve in his government and would be a vital part of Egyptian political life.
Suleiman, 74, said he was running for office in response to public demands for a counterweight to Islamist influence.
"This is why they sought me, as a balance between Islamists and civilian forces," said Suleiman.
He describes himself as a devout Muslim but said that Egyptians fear their country is being turned into a theocracy.
The Brotherhood, in addition to dominating parliament, chairs an assembly that was formed to write a new constitution before a court suspended its activities last week. Liberal groups had walked out of the assembly, saying it failed to reflect Egypt's diversity.
"Many people felt that the state is going to the Muslim Brotherhood - in parliament, in government and now the presidency," Suleiman said, while conceding that the Brotherhood was "a very important segment of Egyptian society."
(Additional reporting by Marwa Awad and Ahmed Tolba; Writing by Yasmine Saleh; Editing by Tom Pfeiffer and Anna Willard)