CAIRO—The three most prominent and divisive front-runners in Egypt´s presidential elections indicated Sunday they were appealing their exclusions from presidential elections scheduled for next month— demanding a reversal of decisions that are likely to stoke popular outrage across Egypt´s political spectrum.

Farouq Sultan, a judge who leads the commission, said Saturday night that Muslim Brotherhood candidate Khairat al-Shater, former intelligence chief Omar Suleiman and hard-line Islamist preacher Hazem Abu Ismail were among 10 candidates barred from running.

Mr. Sultan gave no explanation for the candidates´ exclusion in his statement. The 10 presidential hopefuls had 48 hours to appeal the decision. Late Sunday, Egypt´s state-run news media reported that Mr. Suleiman had submitted his appeal, while the two others said they would submit their appeal documents before Monday.

If the excluded presidential candidates fail in their appeals, the popular backlash is likely to be powerful.

The move threatens to launch a renewed round of instability only a month before Egypt´s first post-revolutionary presidential elections and little more than two months before the military has promised to hand over power to an elected civilian president.

"This is a purely political decision," said Mourad Mohamed Ali, the head of Mr. Shater´s presidential campaign. Mr. Ali said the decision was directed by Egypt´s interim military leaders who, he said, were working to undermine Egypt´s revolution and reconstitute the ousted regime of former President Hosni Mubarak.

"It´s not about whether Shater will be able to go for the election or not. We are talking about human rights. We are talking about legitimacy. We are talking about the direction of Egypt," he said.

Yet Mr. Suleiman´s exclusion along with that of hard-line Islamists such as Mr. Shater and Mr. Abu Ismail complicates perceived notions that the election commission´s decision was a purely political gesture to check the rise of Islamist politicians.

Since Mr. Suleiman announced his participation in the race last week, furious Islamist and liberal activists alike maligned him as an extension of the military regime. The criticism became so pervasive that the normally tight-lipped intelligence services said Saturday that they weren´t supporting or campaigning on Mr. Suleiman´s behalf.

Egyptian state-run media reported Saturday night that the presidential elections commission said Mr. Suleiman was disqualified because he failed to gather supporters´ signatures from at least 15 different governorates in accordance with campaign laws.

Mr. Ali speculated that the commission may have excluded Mr. Suleiman as a token gesture of fairness to justify sidelining Islamist candidates. The Brotherhood has "indicators" that the nominally independent election commission is operating under orders from the ruling Supreme Council of the Armed Forces, or SCAF, he said.

The SCAF appointed the judges who form the election commission.

If the commission´s decisions are upheld, the new presidential campaign landscape will remain a battle between Islamists and pro- military politicians, albeit with fewer fiery personalities and lower stakes.

The commission may have removed the frontrunners to deflate growing tensions between the military regime and Islamist politicians who have spent the past several months locked in a power struggle said Khalil Al Anani, an expert on Islamist groups at Durham University in the U.K.

In another potentially destabilizing development Sunday, representatives from nearly 20 Egyptian political parties met with the head of the SCAF, Field Marshall Hussein Tantawi, to discuss jump- starting stalled efforts to draft a constitution.

A court decision last week suspended an Islamist-dominated constituent assembly charged with drafting a new constitution. The court ruled that it was unconstitutional for 50% of the assembly´s membership to draw from the Egyptian parliament.

According to the Egyptian media and people familiar with the meeting, Field Marshall Tantawi urged political leaders to agree to finish drafting the constitution before the promised handover of power to civilians on June 30. He also asked that the new 100-person constituent assembly contain no members of parliament. Mustafa al- Nagar, a co-founder of the secular-minded Justice Party, said over his official Twitter account that Field Marshal Tantawi wanted prospective constituent assembly delegates to complete the founding document before presidential elections that begin on May 23.

The military and political parties are set to continue their deliberations over the constituent assembly´s membership next week. While the more inclusive parameters are likely to please the at least 20 liberal politicians who stormed out of the Islamist-dominated assembly in protest last month, it will almost certainly anger the powerful Brotherhood, who in the past have angrily rejected any military interference in the constitutional drafting process.

The presidential election commission´s decision could clear the presidential field for Amr Moussa, the popular former secretary general of the Arab League, to dominate the vote. Mr. Moussa, who also served as Mr. Mubarak´s minister of foreign affairs, has spent most of the past year leading the presidential pack, according to poll figures.

The stripped-down race could also benefit moderate Islamist Abdel Moneim Aboul Fotouh, who was a reformist member in the Muslim Brotherhood before he was kicked out last summer when he opted to run for president against the group´s wishes.

Supporters for both Islamist candidates have demonstrated a willingness to take to the streets in defense of their candidates.

Thousands of mostly Islamist demonstrators filled Cairo´s Tahrir Square on Friday to demand that the military leadership approve a law excluding Mr. Suleiman from the race because of his connections to the ousted regime of Mr. Mubarak.

Sharing the same space and many of the same chants were thousands of supporters of Mr. Abu Ismail. Mr. Abu Ismail´s candidacy has been under threat for weeks since revelations surfaced that his late mother held American citizenship.

Under a constitutional declaration passed by the military last March, the children of foreign nationals are ineligible to run for president.

Mr. Ali said the election commission excluded Mr. Shater because of a 2006 sentence to seven years in prison on charges of money laundering and participating in allegedly treasonous student militia exercises. The SCAF released Mr. Shater last year and pardoned him late last month, several days before the Brotherhood announced his candidacy. (Copyright © Dow Jones & Company, Inc.) 04/16/12)