Former Prime Minister Ehud Olmert will begin  testifying Tuesday in his ongoing corruption trial, in the Jerusalem District Court. He will be the first defense witness.

On Monday, the court turned down Olmert's request to postpone his testimony for two weeks for medical reasons.

Individuals close to the former premier said he does not intend to battle the prosecution from the witness stand.

"Olmert has already been through several [difficult] situations in his life, including ordeals even more stressful and more nerve-racking than this," said one. "He's not planning any fights or polemics. He has no intention of turning this into a boxing match, but will address [the charges] seriously."

Over several court sessions, Olmert will respond to the three main charges against him: double-billing nonprofits for the same overseas flights and using the surplus to fund personal vacations, receiving cash-filled envelopes from American Jewish businessman Morris Talansky, and improperly interfering in decisions at the Industry Ministry's Investment Center. Most of the alleged offenses occurred while he was either industry minister or finance minister.

Among the issues that Olmert is expected to be asked about is testimony by his good friend, attorney Uri Messer, who said he kept hundreds of thousands of shekels in cash for Olmert at a safe in his office, and by his travel planner, Rachael Risby-Raz, who said Olmert was fully aware of the double-billing.

The trial is expected to continue through the summer, at least.