TEL AVIV, Israel -- Over the past two years, Prime Minister Ariel Sharon has emerged as the ultimate political survivor, fending off repeated attempts by hard-liners within his party to punish him for his withdrawal from the Gaza Strip.

The former general dodged the latest challenge to his leadership of the Likud Party on Monday, narrowly winning a ballot that was widely seen as a referendum on his rule and the recently completed withdrawal.

"The argument over whether or not Sharon's vision was the Likud's vision is over with this vote," Roni Bar-On, a pro-Sharon lawmaker, told Israel Radio.

But dissidents within the Likud Party led by Benjamin Netanyahu said Sharon still had something to prove.

Uzi Landau, a prominent opponent of Sharon, said it was now up to the prime minister to unify the party he helped found. "If he wants, it will be unified. If he continues his past practices, it will not."

Monday's vote by the 3,000-member Likud central committee was ostensibly over a procedural issue: whether to hold elections for party leader in April, as scheduled, or move up the primary to November. But Sharon and Netanyahu said the ballot amounted to a vote of confidence in the prime minister.

Netanyahu, who accused Sharon of abandoning the hawkish Likud Party's nationalist roots by carrying out the withdrawal, pushed for an early primary to capitalize on anger against the prime minister. Sharon opposed any change.

Likud members voted 1,433 to 1,329 -- a margin of just 104 votes -- in favor of keeping the schedule intact, according to official results announced just after midnight. Turnout was 91 percent. As the results became apparent, Sharon's supporters at the site of Monday's vote popped open champagne bottles and danced in celebration.

Netanyahu, a former prime minister, conceded defeat Monday in the 52-48 percent vote, but said he would continue his campaign to oust Sharon. He said the close vote showed that the party remains bitterly divided, with many members opposed to Sharon's concessions to the Palestinians.

"I expect to see this camp with all its force when it fights for the path of the Likud in the primaries and I have no doubt in the second phase we will win and the Likud will win," Netanyahu said.

Sharon confidants said that with a defeat, he likely would have quit Likud and competed in elections as the head of a new centrist party. Such a run by Sharon, who is popular among the Israeli general public, would strengthen the political center, pushed Likud to the political fringe, and likely improve chances of a Mideast peace deal.

Sharon has expressed hope that the Gaza withdrawal could lead to a resumption of peace talks, and he has voiced support for an independent Palestinian state.

The prime minister is still expected to face a tough challenge from Netanyahu in the party primary. And his junior coalition partner, the centrist Labor Party, has hinted at leaving the government and forcing early elections if peace efforts stall. Elections are currently scheduled in November 2006.

Sharon has brushed off repeated attempts by party hard-liners to defeat him since announcing plans for the Gaza withdrawal nearly two years ago. In a boost for Sharon, one of the Likud "rebels," Gilad Erdan, said after Monday's vote that he would call on the party to line up behind Sharon.

Polls in recent days had shown Netanyahu with as much as a 12-point lead among Likud voters, and a barrage of rockets launched at Israel by Palestinian militants was expected to further bolster Sharon's opponents. Netanyahu has repeatedly warned the Gaza pullout would encourage Palestinian violence.

Late Sunday, Sharon was thwarted from addressing a party convention when his microphone cut out twice. Likud officials said the sound system was sabotaged. After waiting nearly half an hour, Sharon left without speaking.

In response to the rocket attacks, Israel launched a wide-ranging offensive against militants across Gaza and the West Bank over the weekend. Sharon's critics and Palestinian militants have suggested the offensive was aimed at bolstering the prime minister ahead of Monday's vote.

Early Monday, Israeli aircraft attacked suspected weapons factories around Gaza City as well as the southern Gaza towns of Rafah and Khan Younis. The airstrikes knocked out power to the eastern part of Gaza City and caused damage to several buildings, but no injuries were reported.

The army said its targets included an access road leading to a rocket-launching site in northern Gaza, and weapons-manufacturing factories and storage facilities belonging to various militant groups.

Later Monday, aircraft fired missiles at an empty field militants used to launch rockets at Israel, in a strike meant to deter further attacks, the military said.

Israel pressed ahead with its air campaign despite Hamas leader Mahmoud Zahar's call to end the group's rocket attacks. Zahar said he wanted to prevent further Israeli attacks.

The Bush administration has backed Sharon's military offensive, and State Department spokesman Sean McCormack said Monday that Hamas launched attacks on Israel after the statement was made.

"We understand the situation in which Israel finds itself," McCormack said. "And we fully understand Israel's right to defend itself."

Even if Hamas stops its rocket attacks, it remained unclear whether smaller militant groups would follow suit. Islamic Jihad said it would not observe the truce after an Israeli airstrike Sunday killed one of its top commanders in Gaza.

Israeli security officials said they would wait to see whether the Palestinian attacks would end before calling off the offensive. On Monday, militants launched two mortar shells into southern Israel, but the army said there were no injuries or damage.