Despite several hours of apparently successful surgery, doctors at Jerusalem's Hadassah hospital where Sharon is being treated announced that the prime minister remained in a critical condition. Although his doctors would not speculate on the extent of any lasting brain damage, medical experts have said that there is little chance of his faculties not being seriously impaired.

Deputy leader Ehud Olmert was named acting prime minister and he immediately convened the cabinet for a special session. 'This is a difficult situation that we are not accustomed to,' Olmert said at the cabinet meeting. '[But] Israel's strength will allow it to face the situation.'

Sharon's illness comes only weeks after he suffered from a minor stroke in December and ahead of planned Israeli and Palestinian elections scheduled for March and late January respectively. Despite the graveness of the situation, general Israeli elections would be held as originally planned on 28 March, Olmert said.

Sharon's newly formed centrist party, Kadima, has been widely predicted to win the vote, but analysts have questioned whether the party can sustain its high level of support without the former Likud leader, who has held the prime minister position since 2001. Already, there is speculation that Sharon's successor at Likud, Benjamin Netanyahu, could emerge victorious as Olmert and other members of both Kadima and the Labour party led by Emir Peretz are perceived to lack the necessary credentials to achieve a peace deal with the Palestinians.

Sharon's illness will certainly 'increase the uncertainty we are facing to get back to the peace process', said Palestinian Authority (PA) deputy prime minister Nabil Shaath. The growing uncertainty in Palestinian politics could further stall any progress. The Palestinian Legislative Council (PLC) elections, planned for 25 January, have been jeopardised by Israel's refusal to allow voting in east Jerusalem. PA President Mahmoud Abbas has said that elections would be postponed if Israel did not reverse its decision. However, Hamas, who attracted a large vote in municipal elections last month, has refused to accept any such delay.