Prime Minister Ariel Sharon and rival Benjamin Netanyahu are neck-and-neck in a Likud party ballot next week that could redefine Israeli politics after the withdrawal from Gaza, a poll showed on Thursday.
The Likud executive, which opposed the pullout for defying the party's traditional rightist ideology, votes on Monday on Netanyahu's motion to advance a leadership primary to November in an extraordinary move to oust a popular serving premier.
Aides suggest the ex-general will quit Likud if he loses the Central Committee vote and enter the next general election as leader of a new centrist party mining public support for what he calls "disengagement" from conflict with the Palestinians.
A poll published in the Haaretz daily showed 45.5 percent of the 3,000 committee members favour an early primary, against 40.3 who want it staged in April as originally scheduled.
But 11.5 percent said they had no opinion and 2.7 percent refused to answer, indicating the contest was too close to call.
Israel's next election is due in November 2006. But an early primary would almost certainly bring it forward by undermining Sharon's tactical coalition formed with the centre-left Labour party to get the Gaza evacuation plan past Likud rebels.
Whether Sharon bolts Likud and takes pro-pullout allies with him could hinge on the margin of Monday's vote.
A win for Sharon would derail the challenge from Netanyahu, a fierce critic of the Gaza withdrawal. If Sharon loses only narrowly, he could hang on to see if polls shift his way ahead of the primary - a possibility if Palestinian militants stick to a truce and Israeli rightist anger over the pullout fades.
If Sharon is routed by Netanyahu, analysts predict he would waste little time breaking away from Likud to take advantage of cross-party support for his disengagement policy, welcomed abroad as a potential springboard to Middle East peace talks.
Another poll showed Sharon would comfortably win re-election if he struck out on his own with loyalists from Likud.
The survey in the biggest daily Yedioth Ahronoth daily found Sharon would win 36 parliamentary seats, four less than Likud's current total, to 14 for a Netanyahu-led Likud. It showed Labour would also outstrip a Likud under Netanyahu with 16 seats.
Netanyahu was unimpressed. "Let the polls give him 400 seats, it has no meaning," he told Israel Radio. "When parties split with no real path they end up with nothing."
Netanyahu began a quest to remove Sharon from Likud's helm after quitting as finance minister in August to protest at the first uprooting of Jewish settlements from land Israel occupied in a 1967 war and where Palestinians seek independence.
Settlers whose cause Sharon championed for decades and their rightist supporters in Likud and religious nationalist parties condemned the pullout as a reward for Palestinian violence.
But most Israelis backed the scrapping of all 21 Gaza settlements and four of 120 in the West Bank, agreeing they had no strategic or economic value.
Some analysts say Sharon would use any third term in office to scrap some isolated West Bank settlements, but would keep big blocs near Jerusalem and "strategic" ones near Israel's border.