Egypt’s presidential commission excludes 10 of the 23 candidates from presidential race, including Muslim Brotherhood candidate Khairat el-Shater, left, Salafist presidential candidate Hazem Abu Ismail, right, and former Egyptian intelligence chief Omar Suleiman, center. (AFP/Getty Images)

Egypt’s presidential election commission on Saturday disqualified the top two Islamist contenders and the country’s former spy chief, sending shock waves through the volatile political establishment ahead of next month’s vote.

In all, the commission ruled 10 of the 23 presidential hopefuls ineligible, triggering irate reactions from factions that could mobilize mass protests and raising the prospect of renewed chaos that could mar the country’s first democratic presidential election.

The most high-profile among the excluded contenders are Hazem Abu Ismail, an ultra-conservative Salafist preacher; Khairat el-Shater, a multimillionaire and the Muslim Brotherhood’s top strategist; and Omar Suleiman, ousted president Hosni Mubarak’s spy chief, who joined the race at the last moment.

The candidates have 48 hours to appeal the disqualifications, which were announced Saturday night on state television. The commission will release a final list April 26.

If they candidates do not prevail, the race will likely have just three front-runners: longtime diplomat Amr Moussa; the Brotherhood’s backup candidate, Mohammed Mursi; and Abdel Moneim Aboul Fotouh, a moderate Islamist.

The commission made the decision under siege Saturday. Its office was thronged by Abu Ismail supporters demanding that he be allowed to run. By nightfall, the protests had dissipated, but the headquarters remained under tight security.

Abu Ismail was disqualified because his late mother was a dual Egyptian and American citizen, a violation of Egyptian law. Abu Ismail has staunchly denied that his mother held U.S. citizenship, and his supporters called for mass and violent protests to “storm” Egypt, using Facebook groups to organize.

On the Salafist channel El Hekma, Abu Ismail called for calm until Sunday but told his supporters to be “prepared.”

Abu Ismail also threatened in the phone interview to expose bribery and fraud cases if he was not reinstated, depicting the exclusion as a conspiracy against him.

Shater was disqualified because he was previously a political prisoner. He was pardoned after his release last year. His media adviser said disqualifying his candidate would be the same as if South Africa had barred Nelson Mandela for running for office because he was once a political prisoner.

“This is an unfair and undemocratic decision,” said Mourad Mohammed Aly, the adviser. “Of course we will appeal, and at the same time we will take all measures necessary to make sure Egyptians get their freedom.”

Meanwhile, the head of the Supreme Council of the Armed Forces, Mohammed Hussein Tantawi, called for a crisis meeting with the heads of political parties on Sunday, according to the state-run Middle East News Agency.

Suleiman was disqualified because of discrepancies in the signatures of support he gathered for his nomination, according to the state-run Al-Ahram newspaper.

The decision against him will probably be welcomed by revolutionaries, liberal parties and Islamist groups that were enraged by the Mubarak crony’s decision to run. Suleiman is blamed for the repression and torture of Islamists during Mubarak’s rule.

On Twitter, Egyptians wrote and retweeted repeatedly “Omar Suleiman is out, Egypt is free.”

The Suleiman campaign’s official Twitter account said he would also appeal.

Abu Ismail’s disqualification will likely be met with the most anger, said analyst Diaa Rashwan from the Al-Ahram Center for Political and Strategic Studies. In a poll conducted in March by the center, Abu Ismail — the only Salafist in the race — came in second, after the former Arab League Chief Amr Moussa. Shater and Suleiman were not included in the poll.

If Shater is disqualified, the Brotherhood has a backup candidate, Mohammed Mursi, the secretary general of its political wing. If Suleiman is barred, his supporters will likely shift to Mubarak-era Prime Minister Ahmed Shafiq. But Salafists have no alternative, Rashwan said.

“They will have the biggest reaction,” he said.

Abdel Moneim Aboul Fotouh, a progressive Islamist who split from the Brotherhood to run, condemned the exclusion of some of his opponents.

“We don’t believe that in Egypt after the revolution people’s political rights should be taken away from them based on unfair rulings during Mubarak’s era or undocumented allegations,” he said in a statement.

Special correspondents Ingy Hassieb and Haitham Mohamed contributed to this report.