Head surgery planned for Ariel Sharon has been postponed because the comatose Israeli prime minister has a respiratory infection, his doctors say.
Ariel Sharon has been in a coma since January
Medics at Jerusalem's Hadassah Hospital described the infection as "mild".
Tuesday's operation had been aimed at restoring part of Mr Sharon's skull, removed during previous surgery after his massive stroke on 4 January.
Interim Prime Minister Ehud Olmert assumed Mr Sharon's powers in January and is expected to take his title soon.
"The surgery that Prime Minister Ariel Sharon was to undergo today has been delayed due to a slight infection discovered this morning in his respiratory tract," Hadassah Hospital said in a statement.
The operation would have been Mr Sharon's eighth bout of surgery following his brain haemorrhage in January.
ARIEL SHARON'S HEALTH
18 Dec 2005: Sharon suffers minor stroke
4 Jan 2006: Sharon rushed to hospital one day before scheduled heart surgery with major stroke
4/5 Jan: Undergoes two operations overnight
6 Jan: Third round of surgery
9 Jan: Doctors start to try to rouse him from medically induced coma
15 Jan: Has tracheotomy to help to wean him off respirator
1 Feb: Doctors insert feeding tube into stomach
11 Feb: Has infected area of colon removed after condition worsens
The 78-year-old has since been in what doctors describe as a "critical but stable condition".
Hospital officials said recently that a decision would be made soon on whether to move Mr Sharon to a nursing home for long-term comatose patients requiring constant medical care.
A political party founded by Mr Sharon before his stroke, Kadima, won Israel's general election last week.
Mr Olmert - who replaced Mr Sharon as Kadima's chief - is expected to assume the title of prime minister in the coming weeks.