Doctors have said that Israeli Prime Minister Ariel Sharon's condition remains unchanged after a second night in hospital following a major stroke.
Hospital officials say the prime minister will undergo a brain scan on Friday to check for further bleeding.
The 77-year-old leader will remain sedated in an ‘induced coma’ until at least Sunday, doctors said.
Correspondents say aides to Mr Sharon are working on the assumption that he will not be capable of resuming work.
Deputy leader Ehud Olmert has assumed power and chaired a special cabinet meeting on Thursday, but attention in Israel is beginning to turn to an uncertain political future.
The country is due to hold a general election on 28 March, which will go ahead as planned.
Mr Sharon had recently formed a new political party, Kadima (Forward), after defecting from the right-wing Likud party.
The BBC's Jeremy Bowen says his stroke changes every political calculation with no-one, including Ehud Olmert, commanding such Israeli trust.
Our correspondent says at any rate a successor may not have the will, experience or desire to follow Mr Sharon's plans.
Brain damage fear
The director of Hadassah Hospital, Shlomo Mor-Yosef, said on Friday morning that all of Mr Sharon's vital signs had remained unchanged overnight.
These included his blood pressure, his pulse and his inter-cranial pressure, the most important indicator.
‘This is a positive sign,’ said Mr Mor-Yosef.
Earlier the deputy director Shmuel Shapira called for patience.
‘He is in a medically-induced coma and on a respirator,’ Shmuel Shapira told the Associated Press.
‘This is a stage that requires much patience. We don't expect a tremendous turnaround. We're hoping for the best.’
The Israeli newspaper Haaretz reports that Mr Sharon's doctors do not expect him to recover from the stroke and the brain haemorrhage that followed.
They fear the prime minister has suffered serious and irreversible brain damage, Haaretz says.
Suspicion has fallen on blood-thinning drugs prescribed after a minor stroke Mr Sharon suffered in December.
Blood thinners are a regular and correct form of treatment for minor strokes caused by blood clots, doctors say.
But medical experts say those drugs would greatly increase the chance of a potentially-fatal brain haemorrhage following a second stroke.