BBC News website correspondent Martin Asser looks at the consequences in Israel and the region of the health crisis suffered by Prime Minister Ariel Sharon.
What is the immediate political impact of Ariel Sharon's stroke?
Mr Sharon's political future depends on the assessment his doctors give to Israel's Attorney General, Menachem Mazuz. If they say the prime minister's stroke has left him "permanently incapacitated", the cabinet must elect one of its members to take over as acting prime minister.
Doctors have been waiting to revive the comatose Mr Sharon before passing judgement on his long-term health and mental capacity.
Restrictions on who can stand - contenders must be members of parliament and belong to Mr Sharon's ruling Kadima party - mean that five ministers are eligible, but the most likely winner is former Jerusalem mayor and Finance Minister Ehud Olmert.
Mr Olmert is already acting prime minister by default, as Mr Sharon has been declared "temporarily incapacitated". Constitutionally, this state of affairs could continue for 100 days, although elections had already been set to take place before then - on 28 March.
What are the prospects for his newly formed party?
Ariel Sharon founded his new centrist party, Kadima, late last year to push through his presumed, but not-fully-outlined plan to carve out Israel's borders unilaterally, without peace negotiations with the Palestinians or Syria, whose Golan Heights were occupied by Israel in 1967.
Although Mr Sharon managed to pull troops and settlers out of the occupied Gaza Strip and a small part of the West Bank last August, the move split the right-wing Likud party which he co-founded in the 1970s.
It also alienated the pro-settlement constituency which dominates Israeli right-wing politics. Mr Sharon moved to rid himself of their control.
Kadima has yet to formalise its organisational structure and is based entirely around Mr Sharon's leadership skills and standing with the Israeli public.
However, many Israelis share Kadima's aims and it could do well in elections.
Support from fellow Kadima politicians has continued for Mr Olmert as Mr Sharon's deputy and potential successor - but it remains to be seen whether the glue provided by Mr Sharon will hold the new party together.
What is the medical row over Mr Sharon's treatment?
Many questions have been asked about medical decisions in the prime minister's case.
Why was he kept on potentially harmful anti-coagulant drugs while waiting for a heart operation? Was the heart operation truly necessary and why was it delayed? Why was the prime minister taken to Jerusalem rather than a hospital closer to his ranch where he was taken ill?
Has his condition been "over-treated", leaving him physically and mentally impaired and with little chance of recovery?
Hadassah hospital has declined to address specific questions but insists all its decisions have been necessary according to the case.
"We are busy treating the prime minister and fighting for his life, and are not engaged in anything else," said a spokeswoman.
What are the chances of a medical recovery?
The prime minister suffered severe haemorrhaging in his brain over several days, which medical experts say could leave him paralysed, physically or mentally impaired, or even in a persistent vegetative state.
One of Mr Sharon's team, apparently in an unscheduled interview, said he would never be able to function as prime minister again.
Any speculation about Ariel Sharon's health is inevitably tinged with politics and the hospital has given very little away so far - especially in avoiding any official suggestion that he may not fully recover.
Some commentators say ambiguity helps Kadima because the prime minister's health crisis has brought a temporary suspension of electioneering in Israel as most of the nation rallied behind the stricken Mr Sharon.
How have political opponents reacted?
On the Israeli side, politicians have mainly kept a disciplined, respectful silence despite looming elections. No one appears to have tried to make political capital out of the crisis.
Only on the extremes of the settler movement, some of whose members put a death curse on Mr Sharon over the Gaza pullout, has Mr Sharon's condition been celebrated.
Some right-wing rabbis have meanwhile called on supporter to follow their hearts, perhaps praying for Mr Sharon's recovery, but not his return to power.
Mainstream Palestinian leaders said they wanted Mr Sharon - the first Israeli leader to dismantle Jewish settlements - to survive and continue along that path.
But the stance is tempered by the experience of the prime minister shunning political negotiations with them, only holding "contacts" to fine-tune his unilateral steps.
Many ordinary Palestinians insist there is no difference between Mr Sharon and other Israeli leaders, though he is held in particularly low regard because of his bloody military record.
The leader of Islamic militant group Hamas - which commentators say is poised to win Palestinian legislative elections on 25 January - said "the whole region will be better off with him absent than with him present".