WASHINGTON — As Israelis celebrate their nation’s 60th anniversary, a political scandal hovering over Prime Minister Olmert could trigger a replay of the most consequential election of the Oslo years: Ehud Barak versus Benjamin Netanyahu.

The scandal surrounding Mr. Olmert is so sensitive that the Israeli press has been officially censored from reporting its details, after police interviewed the prime minister this week on short notice to discuss new developments in a wide-ranging corruption probe. Mr. Olmert has publicly denied any wrongdoing when questioned about prior allegations of corruption.

According to American news reports, however, the current case, the latest in a succession of political challenges to the Mr. Olmert’s government, involves alleged bribes from a Long Island businessman, Morris Talansky. The Israeli press in recent days has been rife with speculation that the scandal could force early elections.

Mr. Olmert’s political career was widely believed to be finished following the release of the Winograd commission’s critical assessment of his government’s handling of the 2006 war with Hezbollah. Although the prime minister defied the odds then and soldiered on, the chief Washington correspondent for the Israeli newspaper Haaretz, Shmuel Rosner, said the latest scandal could be more damaging.

“This looks very serious,” he said. “Most of the people I talk to, including legal and political analysts, say this could be it.”

Israel’s negotiating partner, Palestinian Abbas of the Palestinian Authority, already has signaled through aides that substantive negotiations are impossible, given the allegations against Mr. Olmert and the possibility of new Israeli elections. The White House also announced that when President Bush visits Israel next week to mark Israel’s 60th anniversary, he will not seek a meeting with Messrs. Olmert and Abbas together.

“This did not seem the time for a big, high-level, three-way event,” National Security Adviser Stephen Hadley told reporters yesterday. “It just doesn’t feel right as the best way to advance the negotiation.”

Mr. Rosner set out two possible scenarios if Mr. Olmert steps down: an accession by the current foreign minister, Tzipi Livni, or an election fight between two former prime ministers, Mr. Barak, the defense minister, and Mr. Netanyahu.

Mr. Olmert’s resignation would empower Ms. Livni to take over as caretaker premier while the country sets a date for new elections. The Knesset could ratify Ms. Livni as prime minister, and she could conceivably serve out Mr. Olmert’s term.

In the event of elections, Messrs. Barak and Netanyahu would likely square off against each another for the top job in the Israeli government.

“I think the contest will be between Barak and Bibi,” the director of the Hudson Institute’s Center for Middle East Policy, Meyrav Wurmser, said. “They are the known quantities. They have parties behind them that will push them along and they both want to be prime minister.”

Mr. Barak is a member of Israel’s more liberal Labor Party, while Mr. Netanyahu is the leader of the more conservative Likud Party. When Prime Minister Sharon withdrew Israeli soldiers and settlers from Gaza in 2005, Mr. Netanyahu opposed him, spurring Mr. Sharon to form the centrist Kadima Party, which Ms. Livni and Mr. Olmert then joined.

Ms. Wurmser said Ms. Livni has many qualities that appeal to Israeli voters, but that she lacks “a killer political instinct.” The foreign minister has been a vocal proponent of the current peace talks with the Palestinian Arabs, while in the last year Messrs. Barak and Netanyahu have been more skeptical of Mr. Olmert’s initiative.

Indeed, Mr. Barak has been one of Israel’s most forceful advocates for the completion of the separation barrier the Jewish state began building in 2003 to prevent suicide bombers from entering its pre-1967 borders.

The new face of Mr. Barak is a change from when he bested Mr. Netanyahu in the 1990s and became the first and only Israeli prime minister to offer sections of Jerusalem up for the capital of a Palestinian Arab state.

Ms. Wurmser said of Messrs. Barak and Netanyahu: “They are not that far apart on political issues. Barak is the Labor Party’s man on security, which once upon a time was Rabin. Bibi has the credibility of a hard-liner.”