jerusalem | When Ariel Sharon decided to have the full Likud Party vote on his controversial plan to withdraw from the Gaza Strip and part of the West Bank, it seemed like a desperate gamble.

The chances that Sharon’s party would approve the plan were uncertain, to put it mildly. Yet just two weeks later, it looks as if the prime minister’s gamble has paid off and that the Likud will pass Sharon’s plan by a clear majority.

After his mid-April White House meeting with President Bush and the ensuing support of key Likud Cabinet ministers, Sharon is confident he can win the crucial May 2 party vote by a convincing margin.

And though aides insist that Saturday, April 17’s assassination of Hamas leader Abdel Aziz Rantissi in Gaza was planned long before the mini-referendum, pundits believe it will help Sharon garner even more Likud support.

The latest polls, taken after the meeting with Bush but before Rantissi’s assassination, gave supporters of the plan a 10-15 percent lead over opponents in the Likud. Only strong public opposition by Finance Minister Benjamin Netanyahu might have turned the tables — but Netanyahu, after some wavering, announced that he, too, is now on Sharon’s side.

But the Likud is not the only factor that could affect the plan’s success: It still could be delayed or scuttled if Attorney General Menachem Mazuz decides to indict Sharon on corruption charges. The plan also could be modified if the Palestinians finally discard violence in an attempt to stop Israel’s unilateral moves and force Sharon into talks on a negotiated settlement.

Likud opponents argue that withdrawing from Gaza could impede the fight against terrorism, even encouraging more attacks if Israel seems to be fleeing in the face of violence. Rantissi’s killing undercuts those arguments.

Netanyahu, the only Likud leader who could have mobilized enough party support to defeat Sharon, made his backing for disengagement contingent on three conditions: That Israel control all border passages to prevent arms smuggling into Gaza after the army withdraws; that the possibility of refugees returning to Israel be ruled out; and that the West Bank security fence be completed before any withdrawal, and include the main Israeli settlements in the West Bank.

Other heavyweight waverers, most notably Foreign Minister Silvan Shalom and Education Minister Limor Livnat, also have announced their support for the plan. In a sign of the shifting political winds, a series of debates between Sharon and Cabinet Minister Uzi Landau, one of the fiercest opponents of the plan within Likud, were canceled.

Leslie Susser is the diplomatic correspondent for the Jerusalem Report.