Activists who engineered Egypt's uprising have long suspected that the generals would try to cling to power, explaining that after 60 years as the nation's single most dominant institution, the military would be reluctant to surrender its authority or leave its economic empire to civilian scrutiny.

Shafiq's rival in the Saturday-Sunday runoff, Mohammed Morsi of the Muslim Brotherhood, said he was unhappy about the rulings but accepted them.

"It is my duty as the future president of Egypt, God willing, to separate between the state's authorities and accept the rulings," the U.S.-trained engineer said in a television interview. Late Thursday, he told a news conference: "Millions will go to the ballot boxes on Saturday and Sunday to say 'no' to the tyrants."

Senior Brotherhood leader and lawmaker Mohammed el-Beltagy was less diplomatic, saying the judges' action amounted to a "full-fledged coup."