With Israeli Prime Minister Ehud Olmert up against the ropes, members of his Kadima party are already jockeying for position in anticipation of his downfall and possible early elections.

"The Kadima party primary began yesterday, even if nobody declared this officially. Even the prime minister realises that he cannot prevent it from taking place soon," the top-selling Yediot Aharonot wrote in an editorial.

Olmert suffered a stinging one-two blow when his deputy challenged his leadership right after a key ally demanded he quit over a corruption scandal.

Foreign Minister Tzipi Livni, the number two in the government and in Kadima, on Thursday called for unprecedented primary elections in the centrist party, hinting strongly that the scandal-tainted Olmert must go.

She dropped the political bombshell just one day after Defence Minister Ehud Barak, whose Labour party is a key partner in the government coalition, demanded that Olmert step down or face early election.

"The scent of elections is in the air," the Haaretz newspaper said, echoing the prevailing view of political experts.

A poll published by Haaretz said that while Livni is the favourite among Kadima voters, the opposition right-wing Likud party of former premier Benjamin Netanyahu would emerge the winner if an election were held now.

The hawkish Netanyahu vocally rejects any suggestion of a withdrawal from the Golan Heights that was raised when Olmert announced earlier this month his government was involved in Turkish-mediated indirect talks with Syria.

Addressing Israeli settlers in the area which Israel occupied in 1967 and annexed in 1981, Netanyahu said on Thursday that an early election "would allow the people to say no to a withdrawal from the Golan."

Israeli voters believe Olmert, who has weathered political crises, corruption scandals and single-digit popularity ratings since he took office in 2006, must go.

An opinion poll on Thursday found that 70 percent of people surveyed thought he should step down.

Pressure against Olmert, 62, reached boiling point after Jewish-American financier Morris Talansky testified before a Jerusalem court on Tuesday that he had given Olmert vast amounts of cash stuffed into envelopes.

Talansky said he had given at least 150,000 dollars in the 14 years before he became prime minister in 2006, some of which might have been used to fund Olmert's taste for luxury goods.

Olmert has denied any wrongdoing over the allegations that have been simmering since police first questioned him in the affair on May 2. He has, however, acknowledged receiving campaign donations.

The prime minister, who flies to Washington on Monday for a three-day visit and a meeting with US President George W. Bush, has asked Kadima MPs not to do anything until his return, Israeli media said.

A growing number of Israeli lawmakers have said Olmert cannot devote the necessary energy to US-sponsored peace talks with the Palestinians, as well as indirect negotiations with Syria, while at the same time fighting for his own political survival.

But Olmert aides insist it is business as usual in the premier's office.

The prime minister is scheduled to meet Palestinian president Mahmud Abbas on Monday before leaving for Washington.

The meeting "will focus on the ongoing negotiations, the situation on the ground and the truce talks" between Israel and the Islamist Hamas movement in Gaza, which are being mediated by Egypt, senior Palestinian negotiator Saeb Erakat said.

Olmert and Abbas will meet at the premier's official residence in Jerusalem, Erakat said.

In Washington, officials stressed that US Secretary of State Condoleezza Rice's travel plans to the Middle East are unaffected by the corruption scandal.

"I'm not aware that anything that's occurred in Israeli politics in the last few days has made any change in our plans necessary," State Department spokesman Tom Casey said on Thursday.

© 2008 Agence France-Presse