CAIRO — Former President Hosni Mubarak’s health deteriorated rapidly as he was rushed to a military hospital on Tuesday, adding to the uncertainty gripping the nation as the ousted strongman’s longtime opponents, the Muslim Brotherhood, battled his onetime allies in the military for political power.
There were conflicting reports about Mr. Mubarak’s condition. State news media and government officials initially said Mr. Mubarak, 84, had been declared “clinically dead,” and then placed on life support after being taken to a military hospital overlooking the Nile. But by early Wednesday, officials said he was in critical condition but alive.
He had been hospitalized in a prison medical ward after he was given a life sentence 15 days earlier in connection with the killing of demonstrators during the 18 days of protest that ended his rule.
The news of Mr. Mubarak’s failing health spread quickly through Tahrir Square, the symbolic heart of the nation, where hundreds of thousands of demonstrators were protesting against the ruling military council. In recent days the generals had moved to seize the kind of uncontested authority that the former president wielded during his three decades in power.
The confusion over his condition injected new volatility into the country’s growing political and constitutional crisis, even as the two candidates to replace Mr. Mubarak as president declared themselves the winners. Analysts marveled that Mr. Mubarak had lost consciousness at the climactic moment of the struggle over the future of the system he defined for so long, and just two days after the vote to choose his successor.
“It is very Shakespearean,” said Diaa Rashwan, an analyst at Al Ahram Center, a state-financed research institute. “To himself, he is eternal. There can be nobody after him. He does not want to hear the name of his successor.”
On Monday, Mohamed Morsi, a Brotherhood leader, said he had won Egypt’s first competitive presidential election, beating Ahmed Shafik, Mr. Mubarak’s last prime minister. The official vote results are set to be announced later this week, but on Tuesday, Mr. Shafik disputed several vote counts, including in the state news media, that forecast Mr. Morsi as the winner.
A spokesman for Mr. Shafik, Ahmad Sarhan, said he had won 51.5 percent of the vote. But that announcement seemed another tactic in a battle that began before voters went to the polls to select between the two candidates.
Last week, the ruling generals dissolved Parliament, which was dominated by the Brotherhood, saying the move was justified because of a decision by a court of Mubarak-appointed judges. The generals also proceeded to issue their own interim constitution entrenching their power while all but eviscerating the authority of the new president.
Their interim charter also provided them and the Mubarak-appointed judiciary broad sway over the drafting of Egypt’s next permanent constitution.
But the Brotherhood was not about to walk away, and vowed to use the legitimacy of election to rally the public and fight for power. It called for a large street protest in central Cairo, and tens of thousands responded.
As the crowd swelled, a protest leader issued a warning to the military, whose forces had surrounded the Parliament building, to prevent elected members from entering. “We’re giving the forces now standing in front of the Parliament until the official results are announced,” he said, referring to the official election count. “After the official results, if one soldier is standing there — ” he said, before his voice was drowned out by the crowd.
Hours later, in another warning and a show of force, the Muslim Brotherhood led a rally that filled Tahrir Square with protesters. “Down, down with military rule,” they thundered.
“The struggle starts now,” said Mohammed Gamal, one of the protesters. “We are ready to present more martyrs. The people’s legitimacy will not be canceled out by the greed of old generals,” he said.
As he spoke, Mr. Mubarak was being transferred by ambulance to a hospital on the Nile. Officials and the state media said he had suffered a stroke while in the prison hospital ward he had been held since he was sentenced. They said that when he reached the military hospital he suffered cardiac arrest and was placed on life support.
Mr. Mubarak, was last seen in public 17 days ago when he was sentenced to life. Though the judge had pronounced him responsible for a “dark, dark, dark” era of crimes and said he was broadly responsible for the murders, the verdict was followed by days of street protests. It appeared the judge paved the way for Mr. Mubarak to appeal by saying that prosecutors had shown no evidence linking Mr. Mubarak to the killings.
His questionable conviction, and earlier reports that Mr. Mubarak might be released from the hospital because of his health, became a major issue in the runoff to succeed him — Egypt’s first competitive presidential election.
His health deteriorated rapidly when he was flown by helicopter from the courthouse to a hospital ward in a notorious prison where his government’s political prisoners had served their sentences.
The subject of Mr. Mubarak’s health was a taboo, punishable by prison time, when he was president. The flood of reports after his imprisonment led many to speculate that the ruling generals were testing the public reaction in case they decided to move the former president out of prison.
Mr. Mubarak’s lawyer told CNN on Tuesday that his wife, Suzanne Mubarak, was by his side, and he expressed anger that Egypt’s military rulers had not moved him to the hospital sooner.
“If he dies it will be SCAF’s responsibility,” he said.
In Tahrir Square on Tuesday, the news of Mr. Mubarak’s health was met with familiar doubts. “They say Mubarak really died,” said Hatem Moustafa, 22. “Maybe this time it is really true.”
But still, he was not convinced. “I think the military council is saying this so that we will leave Tahrir Square,” said Mr. Moustafa. “They would say anything to get us to leave the Square.”