Sharon's proposal was to invite the dovish Labor Party and Orthodox Jewish to join his teetering government, ensuring a solid majority for his Gaza withdrawal plan in the face of internal opposition from his own Likud Party.
Israeli media reported that the final count of the vote in the Likud Central Committee was 62 percent in favor of Sharon's proposal and 38 percent against.
Sharon proposed removing all 21 Jewish settlements from Gaza and four from the West Bank, reversing decades of support for building and expanding settlements. Many members of his Likud Party rejected his new policy, and his government lost its majority in parliament.
A Sharon loss in the Likud Central Committee vote could have forced new elections and jeopardized the Gaza withdrawal — a centerpiece of efforts to restart peace talks with the Palestinians in the wake of Yasser Arafat's death.
A win would add a partner solidly in favor of the Gaza pullout and resumption of peace negotiations. Some in Labor oppose joining Sharon, but party leader Shimon Peres is strongly in favor.
The Likud body already voted in August against inviting Labor to join the government. But after Sharon fired a key coalition partner for voting against his budget on Dec. 1, his coalition is more tenuous than ever. He warned that the choice now was Labor or elections.
A lengthy electoral campaign would almost certainly delay if not completely thwart his plan to withdraw from Gaza and four West Bank settlements next year.
Members of the Likud body trickled in to the Tel Aviv convention center Thursday to cast their votes. There was no debate — party leaders said the issues are clear and have been discussed at length for months.
Worried about a low turnout that would favor his opponents, Sharon made a rare appeal to his backers to vote.
"I want to say that we are standing before great opportunities and events that could be historical, and I won't let anything or anyone harm the opportunity of the state of Israel to take advantage of these opportunities," he told Army Radio.
Sharon defied his party and his own ideology when he first presented his plan to remove all 21 Jewish settlements from Gaza and four small ones from the West Bank a year ago.
For decades, Sharon was the patron of the settlements, enabling their construction and expansion, and his Likud hotly opposed conceding any land to the Palestinians or creation of a Palestinian state.
Over the past year, however, Sharon has changed his policy, but most of his party refuses to go along.
Sharon says the Gaza settlements, with 8,200 Jews living among more than a million Palestinians, are untenable and must be removed. That would give Israel a better chance to retain its main settlement blocs in the West Bank, where most of the 236,000 settlers there live, he believes, and it would also head off international peace efforts unfavorable to Israel.
Opponents reject evacuating any settlements as a matter of principle and also warn that an Israeli pullout from Gaza would lead to international pressure to withdraw from the West Bank.