New Labour party chief Amir Peretz has threatened to bring down Ariel Sharon's coalition government next week unless the prime minister meets him quickly to agree on a date for an early election.
"If a meeting with Sharon does not take place at the beginning of the week, we may act to topple the government on Wednesday," said Peretz, surprise winner over elder statesman
Israel's parliament is expected to vote on several no-confidence motions on Wednesday. Support from Labour, Mr Sharon's biggest coalition partners, is crucial if the government is to survive the votes.
An election must be held within 90 days if parliament passes a no-confidence vote.
Mr Peretz's camp originally said he and Sharon would meet tommorrow. The prime minister's office offered a meeting for Thursday.
"Sharon acted irresponsibly when he delayed the meeting. I also know political tricks, and intend on keeping my cards close to my chest," Peretz told Israel's Channel Two television.
Mr Peretz has said he would propose to Mr Sharon an election in March or in May, advancing a vote not due until November 2006.
Mr Sharon's spokesmen were not immediate available for comment.