TEL AVIV: Israeli Prime Minister Ariel Sharon's gamble to seek party support for his unilateral "disengagement plan" backfired spectacularly and humiliatingly on Sunday , casting doubt on the future of a plan which could change the map of the Israeli-Palestinian conflict.

His Likud Party rejected the plan, which calls for an Israeli pullout from, and evacuation of, settlements in the Gaza Strip and from four isolated settlements on the West Bank.

By letting the 193,000 Likud members vote on the plan, Sharon had tried to bypass opposition to the plan among his right-wing cabinet colleagues and hardline coalition legislators, and rely on the party membership, which he believed at the time would back him.

Instead, on Sunday night he found himself having to reconsider his options for a plan which three weeks ago won the backing of the United States, in an endorsement Sharon's aides painted as a personal triumph for the premier.

Aware of the looming defeat, Sharon's aides had said over the weekend that the premier would find a way to push his plan forward irrespective of the result. After the results of the exit polls, unidentified aides made the same point.

The extremely low turnout - a little more than a third - could give Sharon an excuse to ignore the referendum, or call for a nationwide one, which he is more likely to win.

Justice Minister Yosef Lapid, leader of the centrist Shinui Party, Sharon's largest coalition partner, made a similar point, dismissing the referendum as an internal party matter and demanding the plan be brought before the cabinet irrespective.

Prior to the referendum, observers had said Sharon's ability to move forward with the plan despite a defeat would depend on the size of the gap between the "nay" and "yea" votes. Exit polls put the gap as high as 24 per cent, which would certainly present an obstacle to moving the plan forward.

Without the backing of his party it will be extremely difficult for Sharon to push the plan through the Likud-dominated cabinet and Knesset. But if it will be tough for the premier to go forward with the plan in light of the referendum results, it would be equally difficult to abandon it. -dpa