Benjamin Netanyahu was set to win a leadership election in Israel's Likud party today, an Israel television and radio exit poll showed.
Mr Netanyahu, a former prime minister, took 47 per cent of the vote to 32 percent for top rival foreign minister Silvan Shalom in a ballot to choose Likud's new chief after the defection last month of prime minister Ariel Sharon, the survey projected.
But his illness raised questions about the 77-year-old prime minister's long-term health and his ability to lead the country if he wins a third term next year.
Likud officials reported very low turnout by among the 130,000 registered party members, but that could be partially a result of mass defections to Mr Sharon's new party.
Remaining Likud members also might be demoralised by a huge plunge in support for the party, which is predicted to lose about two-thirds of its strength in the next parliament.
The winner of the Likud primary must capture 40 per cent of the vote or face a runoff, cutting into valuable campaign time.
Kadima holds a commanding lead in the polls, but the party is built around Mr Sharon - at 77 Israel's oldest prime minister - and his health is likely to become a major campaign issue.
Mr Sharon, who is overweight, was rushed to Hadassah University Hospital in Jerusalem on Sunday evening after showing signs of confused speech, doctors said.
Doctors said he suffered a minor stroke when a small blood clot, which quickly broke up, briefly blocked a blood vessel feeding his brain.
He never lost consciousness or suffered paralysis, and the stroke only temporarily affected his speech, not his memory or cognitive abilities, they said. Sharon was being treated with blood thinners.
"I can say confidently that the stroke will leave no damage or residual effects," said his neurologist, Dr Tamir Ben-Hur. "I would say chances are excellent that he won't have another one."
Ben-Hur said Sharon, who held his daily staff meeting in the hospital this morning, was competent to carry out his duties as prime minister. But Sharon aide Raanan Gissin said it would take some time for him to resume his full schedule.
"Everyone who undergoes this kind of event, it does something to him in terms of perceptions, in terms of the need to hold back and take it easy for a while," Gissin said.
Mr Sharon was being kept in the hospital until tomorrow to ensure he rested, Ben-Hur said.
Mr Sharon's chief of staff, Ilan Cohen, said the premier would return to his Jerusalem residence and get a few days of rest before returning to a full work schedule.
Mr Sharon was at risk for stroke because of his age and obesity. He has never released his medical records, and a right-wing lawmaker and physician, Arieh Eldad, demanded that the prime minister do so now.
AP