JERUSALEM (AP) – Lawyers representing Ehud Olmert on Thursday cross-examined a key witness in a corruption probe against the Israeli prime minister, hoping to discredit allegations that Olmert illicitly accepted cash-stuffed envelopes from an American businessman to help fund a luxurious lifestyle.

The businessman, 75-year-old Morris “Moshe” Talansky, appeared nervous in an Israeli court room, drumming his fingers on the table, fidgeting with a plastic cup and at one point asking for a break. He insisted he told the truth in previous testimony.

The questioning of Talansky is seen in Israel as perhaps Olmert’s last chance of political survival. Talansky’s testimony in May seriously damaged Olmert’s credibility among Israelis. The resulting outrage prompted Olmert’s Kadima Party to set new leadership elections, to be held by Sept. 25.

Olmert’s premature departure from office could seriously hamper or delay his government’s efforts to conclude a peace deal with the Palestinians and resume full negotiations with the Syrians.

Olmert has consistently denied any wrongdoing. He has said he will resign if he is indicted. “Today the cracks in the police and state prosecutors allegations will be revealed,” said Amir Dan, a public relations consultant Olmert hired privately to present his position concerning the corruption allegations in media interviews.

“The Israeli public will discover that they (police) are trying to take down a serving prime minister based on unfounded charges,” Dan told Israel Army Radio.

In a new blow to Olmert’s efforts to clear his name, a key member of his defense team resigned this week after he was criticized for suggesting that Olmert accept a plea bargain and resign, rather than face possible prison time, the Haaretz newspaper reported Thursday.

According to newspaper accounts, Shapira felt that Olmert could plead guilty to fraud and breach of trust to avoid prison. The Haaretz report said Olmert and other lawyers on the team opposed the idea, saying the prime minister should stay and fight.

Attorney Ron Shapira’s departure was depicted in the Israeli media as a sign of turmoil inside Olmert’s defense team just as the crucial cross-examination of Talansky was beginning.

Navot Tel-Tzur, a lawyer on the defense team, confirmed Thursday that Shapira is no longer a member of the team. Olmert is reportedly still considering running in the Kadima primaries, hoping that his lawyers will be able to discredit Talansky, an Orthodox Jew who lives on New York’s Long Island but visits family in Israel frequently.

Talansky said Olmert accepted hundreds of thousands of dollars in cash during his tenure as Jerusalem mayor and as a Cabinet minister before he was elected prime minister in 2006. The money went to feed a penchant for expensive cigars, first-class travel and luxury hotels, Talansky charged. His cross-examination is expected to take five days.

Police suspect the money was meant as bribes, although Talansky insisted he never got anything in return, or illegal campaign financing.

In Thursday’s cross-examination, Olmert lawyer Eli Zohar accused Talansky of forgetting details or giving inaccuracies in his earlier testimony.

Talansky responded by saying he might have gotten a few minor things wrong, like the time events occurred, but that in general he was telling the truth. “I never gave a false answer,” he said.

Talansky has agreed to the questioning on his own accord and is not suspected of violating any Israeli laws. He has expressed exasperation with the intense media focus on him. It may take months before police decide whether to indict Olmert.

In the latest revelation in the case, police last week accused Olmert of pocketing thousands of dollars by deceiving multiple sources, including organizations for Holocaust survivors, into paying for the same trips abroad. The widening of the investigation was announced as Olmert was questioned for the third time in the corruption probe.

Olmert has called the most recent accusations “distorted,” charging the police and state prosecutors with trying to bring him down.

Olmert said he felt insulted because he said he had worked hard for the organizations named in the allegations, which included the Yad Vashem Holocaust memorial and the Nazi watchdog Simon Wiesenthal Center.

Olmert’s allies note that he’s been written off before only to emerge intact. This is the fifth major corruption case against him and few thought he’d survive the fallout from his much criticized handling of the war in Lebanon that broke out two years ago.

Legal analyst Moshe Negbi said he doubts attempts to undermine Talansky would help restore Olmert’s standing. “It’s not necessarily true that throwing mud at Talansky, even if some of it sticks, will clean Olmert,” Negbi told Israel Radio.