JERUSALEM - Prime Minister Ehud Olmert, embroiled in a high-profile corruption investigation, announced yesterday that he will resign after his party chooses a new leader in September elections.
The televised announcement injected new uncertainty into Israeli politics and Middle East peace efforts, coming just as Olmert has been intensifying negotiations with the Palestinian Authority as well as Syria.
It also raises questions about the political legacies of both President Bush and Olmert, who have hoped to burnish their reputations by achieving breakthroughs in Middle East peace talks before leaving office.
Olmert's domestic credibility has sunk so low that it is unclear whether he has the legitimacy or political traction to make historic concessions to Arab adversaries at all.
His political weakness might also undermine his ability to work in partnership with the Americans in pursuit of Middle East peace.
The prime minister, speaking live yesterday on Israeli television, passionately reiterated his commitment to peace but acknowledged that the corruption investigations made it impossible for him to continue in his office.
"The current slander campaign," Olmert said, "including by people who truthfully believe in the virtue of the state and its image, raises a question I cannot and will not ignore: What is more important? Is it my own personal justice, or the public good?"
Many commentators described his speech as statesmanlike, allowing him to leave office with a modicum of dignity and the air of a man who - belatedly in the eyes of his many critics - had finally done the right thing.
Previously, Olmert had pledged to resign only if charged. Yesterday, he vowed that he would continue to fight the legal battle and prove his "innocence and clean hands."
Olmert is suspected by the authorities of crimes including bribery, fraud and breach of trust, but he has not been charged with anything.
He admitted to having made "mistakes" in his conduct before he became prime minister in 2006. In one high-profile case, Olmert is suspected of having received tens of thousands of dollars in cash from Morris Talansky, a New York fundraiser and financier, over a period of 13 years.
In the latest case, known here as "Olmert Tours," the prime minister is suspected of having billed multiple state and charitable agencies for the same flights when he was mayor of Jerusalem and a government minister, using the extra money for private family trips. The police and the Justice Ministry publicized details of that investigation July 11.
Several other investigations against him have been pending for months. It is unclear when they will be resolved.
At once composed and defiant, Olmert devoted the first part of his almost 10-minute speech to extolling his government's achievements on issues such as security and poverty. But his most emotional statements were about his commitment to peace.
"I continue to believe wholeheartedly that reaching peace, ending terrorism, strengthening security and establishing a different relationship with our neighbors are the most vital goals for the future of the state of Israel," Olmert said, adding that U.S. support and the leadership of President Bush had "greatly contributed" to the effort.
A White House spokesman, Gordon D. Johndroe, said that Olmert and Bush spoke just before the announcement. "He wishes him well and will continue to work closely with him while he remains prime minister," Johndroe said. He went on to describe relations during Olmert's tenure as "exceptionally close and cooperative" and expressed confidence that the relationship would continue in the future.
A spokesman for the Palestinian president, Mahmoud Abbas, who has staked his own reputation on the peace process, described Olmert's resignation plans yesterday as an "internal affair." The spokesman, Nabil Abu Rudeineh, said, "The Palestinian Authority deals with the prime minister of Israel, regardless if he is Olmert or somebody else."
Olmert said that Israel was "closer than ever" to reaching understandings that might serve as a basis for agreements with the Syrians and the Palestinians, adding that he would work until his last day in office to bring the negotiations to a successful conclusion "that bears hope."
However, six months of intensive negotiations with the Palestinians have not yielded any obvious results, while Syria continues to insist on talking to Israel indirectly through Turkish mediators.
Olmert's drive for diplomatic achievements "might frighten some," said Abraham Diskin, a political scientist at the Hebrew University of Jerusalem. There are Israelis who do not believe in agreements, and others who support the peace process but do not feel comfortable having their leader negotiate desperately with an eye on the clock. "I belong to that second category," Diskin said.
The future of the talks will depend largely on who emerges as Israel's next leader.