Israel is prepared to press ahead with Middle East peace negotiations with or without Ehud Olmert as Prime Minister, the country’s Ambassador to London said yesterday.

Speaking as the embattled Israeli leader began a three-day visit to America, Ron Prosor said that other potential leaders in the ruling Kadima party would pursue talks with the Palestinians should Mr Olmert be forced from office.

Mr Olmert faces a series of corruption charges and Tzipi Livni, his deputy and Foreign Minister, and Ehud Barak, his coalition partner and Defence Minister, have called on him to step down.

There are fears that Mr Olmert’s removal would kill any hopes of progress in US-backed talks aimed at declaring a Palestinian state by the end of the year. However, Mr Prosor, the former head of the Israeli Foreign Ministry, insisted that the political turmoil would not necessarily affect the pace of talks.

He said that if there was a change of leadership in Israel “it might take a bit of time to regroup” but added that all sides understood that they should move forward to reach a deal.

“All the relevant candidates in Kadima, both Tzipi Livni, [Shaul] Mofaz and others . . . will continue the talks with Fayyad [Palestinian Prime Minister] and [President] Mahmoud Abbas,” he told The Times. “On both sides it is obvious that this is the window of opportunity one should really take with both hands.”

Mr Prosor was referring to outside pressure, primarily from Washington, to clinch a peace deal in the region before President Bush’s term expires. The peace moves are also supported by Tony Blair, who is coordinating efforts to raise money for investment in the Palestinian territories.

Britain will be increasing diplomatic pressure soon for a solution. David Miliband, the Foreign Secretary, is expected in Jerusalem next week. Gordon Brown will follow next month.

Mr Olmert has argued that his presence is necessary to help to push the peace process forward. He is credited with playing a key role in secret negotiations being conducted in Turkey between Israeli and Syrian representatives via Turkish intermediaries.

Mr Prosor played down the importance of the contacts, which he said had been going “for quite a while”.

“Personally, I think it is very, very hard to go on two tracks. The political capacity is very limited,” he said. “I feel the Palestinian track is the most important. We have to focus on this.”

Mr Olmert is due to meet Mr Bush today. Talks are expected to focus on peace efforts but will also cover security in the Middle East, particularly Israel’s request for the latest US military hardware. Reports in Israel said that Mr Bush was preparing a “farewell gift” for Mr Olmert of a security package that would include an advance radar system to protect Israel from long-range missile attack.