Egypt’s embattled military rulers appointed a new prime minister Friday as fiery crowds of supporters and opponents took to the streets, exposing the severity of a split over the leading role of the nation’s long-revered armed forces on the eve of parliamentary elections.

As the largest crowd of the week-long protests gathered in central Cairo’s Tahrir Square to demand that Egypt’s military chiefs step aside, thousands of angry Egyptians demonstrated near downtown in support of the generals and “stability.” A small pro-military group also turned out in the port city of Alexandria, where pitched clashes between anti-military council protesters and security forces continued.

“Legitimacy is not in Tahrir,” the military supporters in Cairo yelled. “O freedom, where are you? The people want the fall of Tahrir.”

Meanwhile, tens of thousands of protesters poured into Tahrir Square, the birthplace of what most are calling Egypt’s unfinished revolution. They rejected the appointment of Kamal el-Ganzouri, 78, who had served as prime minister during Hosni Mubarak’s presidency. He was asked to form a new cabinet to replace the caretaker government that resigned this week amid deadly clashes between security forces and rock-throwing demonstrators.

The military chiefs chose Ganzouri after holding intensive discussions with more prominent figures such as Amr Moussa, the former Arab League chief, and Mohamed ElBaradei, a Nobel Peace Prize laureate who formerly headed the International Atomic Energy Agency. Both turned down the job after demanding broad powers, according to political figures briefed on the meetings.

In Washington, the White House called Friday for the new government to be “empowered with real authority immediately” and for elections to go ahead “expeditiously,” leading to a full transfer of power to a civilian government. The U.S. administration has been hesitant to fully support protesters against the Egyptian military, an institution that receives billions of dollars in U.S. aid.

“The U.S. talks about democracy and justice, but on the ground they don’t support it,” said Mohammed Kenawi, a doctor in Tahrir Square. “The U.S. is only worried about their little child, Israel.” Kenawi said he had not slept in days as he treated patients who lost eyes from birdshot or choked on tear gas, and fended off an attack on the field hospital over the weekend.

Aiming to prevent Ganzouri from entering the cabinet building, hundreds marched to the site and started erecting tents. Revolutionary youth movements declared ElBaradei the head of a “national salvation government.” ElBaradei prayed in Tahrir Square on Friday with the protesters.

After a week of bloodshed, the square was calm Friday, having regained its carnival-like atmosphere. Members of the country’s secular elite were among the throng of sympathizers who joined the hard-core demonstrators, many of whom view Tahrir as a battleground they need to hold.

The only bangs were firecrackers during the demonstration, which organizers dubbed “last chance Friday.”

But protester Ibrahim Mohammed appeared traumatized, reeling from the killings and beatings he said he saw committed by riot police over the past week. If the military chiefs cede power, he said, they know that they — like their former boss, deposed president Mubarak, before them — will probably have to stand trial for the deaths of protesters.

“We want someone accepted by the square, not someone from the old regime,” Mohammed said.

The brutal crackdown on protests across the country has left at least 41 people dead and more than 3,000 injured. The violence has mired the nation in a deepening political crisis just three days before landmark parliamentary elections are scheduled to begin. The government announced Friday that the first stage of parliamentary elections would allow people to vote over two days.

The military chiefs had scrambled to find someone to agree to take over as prime minister before Monday’s elections. The cabinet that resigned this week was seen as weak and subservient to the military council that took power after the winter uprising that ousted Mubarak on Feb. 11.

Ganzouri would have “full powers to help him fulfill his duties with complete efficiency,” the state-run Middle East News Agency reported. It was unclear whether that meant the military rulers would hand some of their authority to him.

The Muslim Brotherhood’s political party, Freedom and Justice, appeared to be one of the few groups satisfied with the appointment of Ganzouri. The group decided not to participate in the opposition demonstrations, which prompted other revolutionaries to accuse it of political opportunism.

“There is no other choice. If Ganzouri has the full authority, this will be good,” said Essam el-Erian, vice president of the Freedom and Justice party. “A real cabinet must come after the elections.”

In a televised news conference Friday, Ganzouri appeared anxious. He assured the nation that he accepted the job only after Egypt’s military chief, Field Marshal Mohammed Hussein Tantawi, said the ruling Supreme Council of the Armed Forces did not want to stay in power. He said he could not form a new cabinet until after Monday’s elections.

But demonstrators and opposition politicians said the council’s choice for prime minister showed that it still did not understand their demands.

“This is not an old people’s revolution,” said Islam Gamal el-Shahed, 23, a medical student working in a makeshift clinic in Tahrir Square. “Ganzouri played his part in the old government. We need a strong government to stand up to the military council.”

Down the road, a family stood together, silently holding signs. “The military council is Mubarak. They kill my son and burn your home,” one said. “It’s your turn now.”

Protesters conducted their own informal poll. A survey was passed out to measure support for ElBaradei; Abdel Moneim Abou el-Fotouh, a former top official in the Muslim Brotherhood; and Hossam Issa, a law professor. People filled out the survey, with an option to fill in a different name, and dropped their vote in red trash cans serving as ballot boxes.

“We trusted the military council; we thought they were part of this revolution,” said Fatma Hussein, 26. “We didn’t expect the military to kill us. We’re starting all over again, and this time we’ll do it right.”

Special correspondent Ingy Hassieb contributed to this report.