An Israeli government minister has gone into hiding to try to thwart Ariel Sharon's Gaza withdrawal plan.
Elon may have succeeded in scuppering Sunday's vote
The prime minister intended to fire two cabinet members who oppose the plan, but the dismissal notice has reportedly not reached one of them, Benny Elon.
Mr Sharon planned to ask his government to vote on the scheme on Sunday but, if Mr Elon is not found, the prime minister may have to postpone the vote.
Firing the two hardliners would give Mr Sharon a majority backing the plan.
He announced on Thursday night his intention to fire
Tourism Minister Elon and Transportation Minister Avigdor Lieberman, both of the right-wing National Union party.
A messenger delivered Mr Lieberman's dismissal to him as he exercised at a gym on Friday.
But Mr Elon has not been found.
He told Israel Radio that he had received a call from someone who sounded like the prime minister - but that he could not be sure if it was Mr Sharon or a comedian who impersonates him.
He may already have been in hiding long enough to thwart Sunday's vote, since sackings take 48 hours to come into effect under Israeli law.
Polls suggest most Israelis support Sharon's plans for Gaza
Before the planned dismissals, 11 cabinet ministers approved the plan, while 12 were opposed.
Israeli officials said Mr Sharon had summoned the two hardliners to his office for a meeting to hand them letters of dismissal.
Mr Lieberman said he would have resigned in any case if the Cabinet had voted to back the plan.
"I'm not embarrassed," he told Israel Radio. "I will go to receive the letter firing me."
As well as pulling out of all of the Gaza Strip, except the border zone with Egypt, Mr Sharon plans to dismantle four settlements in the West Bank.
President George W Bush controversially endorsed the plan after talks with Mr Sharon at the White House in April.
But it was decisively rejected by the prime minister's own Likud party in a referendum the following month.
However, Mr Sharon has continued to advance the pullout proposal, buoyed by opinion polls that suggest a majority of Israelis support it.
BBC Jerusalem correspondent Barbara Plett says Mr Sharon may be able to pass the initiative by a slim majority. But then, he may face a government crisis.
Another right-wing party has threatened to pull out of his coalition if the plan is accepted and that would leave Mr Sharon without a majority in parliament.
Bringing the dovish Labour party into government might trigger a split within his Likud party, while inviting religious parties to make up a majority would anger the ardently secular Shinui party.
With polls suggesting a majority of Israelis support the disengagement plan, Mr Sharon may feel his best bet is to call new elections, observers say.