The Muslim Brotherhood’s disqualified presidential candidate, Khairat el-Shater, said Wednesday that Egypt’s military rulers have no intention of ceding real power to civilians and instead are manipulating the law to guide the outcome of the election in their favor and control the writing of the nation’s new constitution.

Shater warned that his elimination from the race was a sign of fraud to come in the first presidential election since Hosni Mubarak’s ouster in February 2011, and he called the process that led to it a “crime against the Egyptian people.” On Tuesday, Egypt’s presidential electoral commission permanently disqualified three front-runners, including Shater, and seven others, leading many to question the legitimacy of the historic vote just weeks before the May 23-24 balloting.

“The military council, in my opinion, is not serious about the handover of power but is looking for a figure that it can control from behind the curtains,” Shater said at a news conference Wednesday. He said the Brotherhood and its political wing, the Freedom and Justice Party, would turn out in Cairo’s Tahrir Square on Friday to defend the revolution, adding, “This Friday is the real handover of power.”

Shater accused the ruling Supreme Council of the Armed Forces of trying to fix the election by eliminating strong Islamist candidates. He also said that the generals had interfered in the formation of the panel tasked with writing the new constitution and demanded a “revision of the procedures.”

The military leaders have botched the 15-month-old transition to what Egyptians had hoped would be a system of democratic governance, critics say. Some attribute the missteps to incompetence, while others say the generals are trying to derail a true transition to democracy.

Shater appeared angry Wednesday, calling the electoral commission — which is made up of Mubarak-era judges — a “gang.” He said, however, that the election should be held on time and urged Egyptians to support the Brotherhood’s backup candidate, Mohammed Morsi.

The once-banned Brotherhood, Egypt’s oldest Islamist group and by far the best-organized political machine in the country outside the military, has seen its influence soar since the revolt last year. Morsi will have the organization’s full weight behind him, but he is seen as a less popular choice than Shater, analysts say.

Outside the electoral commission’s well-guarded headquarters Wednesday, supporters of another disqualified candidate, the ultraconservative Salafist Hazem Abu Ismail, had set up camp, pitching tents on traffic medians, wearing masks depicting his face and passing out fliers denouncing what they called a U.S. and Israeli plot against him.

Abu Ismail was ejected from the race on the grounds that his late mother held dual Egyptian and American citizenship, an allegation he denies.

Abu Ismail, a lawyer turned television preacher, is wildly popular among ultraconservative Egyptians, and his supporters have vowed to sit in outside the commission until he is reinstated. The commission’s latest decisions, however, are not subject to further appeal.

“They accuse us of being extremists when, in reality, everybody is being listened to except us. We’re being isolated,” a cleric told the crowd of hundreds gathered at the sit-in, which the Salafist Nour party endorsed on its Facebook page. “If we give up one Islamist candidate today, they’ll dare to attack another tomorrow. We have to be alert to their plans and conspiracies.”

Abu Ismail’s supporters are left with no alternative in the race, unlike Brotherhood backers or Egyptians willing to vote for a former government figure such as Amr Moussa, who was once Mubarak’s foreign minister.

A cross section of political and revolutionary movements that have often been at odds during Egypt’s turbulent transition — including the Brotherhood, the revolutionary youth group April 6, and liberal and leftist groups — were working Wednesday to organize a united protest Friday.

Special correspondent Ingy Hassieb contributed to this report.