Sharon's Condition Critical After Surgery

The Israeli prime minister, Ariel Sharon, was in a serious condition early today after seven hours of emergency surgery to stop "massive, widespread" bleeding in his brain.

A brain scan after surgery showed bleeding had been stopped, and Mr Sharon was transferred to the intensive care unit, said Shlomo Mor-Yosef, the director of Hadassah Hospital in Jerusalem, where the prime minister was being treated.

"All vital signs are functional and stable. The prime minister is in critical condition," Dr Mor-Yosef said. He did not comment on the extent of brain damage that Mr Sharon, 77, may have suffered as a result of the cerebral haemorrhage, also known as a bleeding stroke.

Mr Sharon's deputy, Ehud Olmert, who was named acting prime minister after Mr Sharon was taken ill last night, met senior members of Mr Sharon's staff early today and convened the cabinet for a special session at 9am. (0700 GMT). "This is a difficult situation that we are not accustomed to," Mr Olmert told the meeting. "Israel, through its determination and strength, will be able to cope with this difficult situation."

Mr Sharon, who has for years been very overweight, suffered a mild stroke on December 18. He had been due to go to hospital today to undergo a heart operation to plug a hole in his heart which doctors believe caused the initial stroke. He was rushed to hospital last night after complaining he felt unwell. A spokesman said the massive stroke developed during the hour-long ambulance journey. Doctors speculated on Israeli television that blood-thinning drugs administered over the past two weeks may have contributed to yesterday's major stroke.

Close associates of the prime minister said they did not expect the prime minister to return to office. His illness throws Israeli politics and diplomacy throughout the region into turmoil in the midst of election campaigns for both the Palestinians and Israel. He had been expected to easily win re-election in March at the head of the moderate Kadima party he created last year. Mr Sharon has been a dominant figure for decades in shaping the Middle East. His death or incapacitation would set back hopes for peacemaking raised by the withdrawal of Israeli settlers from Gaza which Mr Sharon completed in September despite opposition from rightwingers in Israel. Analysts believed a re-elected Sharon government would continue withdrawals from more settlements.

The Ha'aretz newspaper's website said Mr Sharon was paralysed in half his body, and medical expert agreed the prime minister was likely to suffer some serious impairment to his faculties.

"With all due caution, it appears as though the era of Sharon leading Israel has reached its tragic end," wrote Aluf Ben, the paper's diplomatic correspondent.

Palestinian officials said they were concerned that the uncertainty in Israel could overshadow their campaign for elections on January 25. Two US envoys were to have met Mr Sharon today, apparently to urge Israel to reverse a decision to ban Palestinian voting in east Jerusalem. The Palestinian leader, Mahmoud Abbas, has said he may cancel the vote if Jerusalem is excluded. Israel rejects the Palestinians' claim over east Jerusalem as their capital.

"We hope that this will not affect what we had expected of the Israelis," said the Palestinian negotiator Saeb Erekat. If Mr Olmert delays making a decision on Jerusalem, "it means the Palestinian election is going down", he added.

Palestinian militant factions reacted with glee to news of Mr Sharon's illness. "The whole region will be better off with him absent," said the Hamas group. "Sharon was the one who carried out massacres and terrorism for decades against our people." Israelis and world leaders expressed concern and offered prayers for the prime minister. George Bush praised Mr Sharon as "a man of courage and peace" and said he and first lady Laura Bush were praying for his recovery.

Mr Sharon has been prominent in Israeli life for more than 50 years. He has played a part in every one of Israel's wars. He was injured in the 1948 Arab-Israeli conflict, and became a controversial military leader and then a controversial politician. It is only in recent years, with his groundbreaking plan to withdraw from Gaza, that he has become viewed as statesman, earning respect from all sides of the political spectrum.

Mr Olmert, who could emerge as Mr Sharon's successor as head of Kadima, would have a far tougher time in the election than Mr Sharon.