JERUSALEM, Israel - Israeli Prime Minister Ehud Olmert refuses to resign his post despite calls from his own defense minister to step down. But his days in office may be numbered.

Meanwhile, three of Israel's four largest parties are getting ready for new elections, as Olmert tries to fight several legal battles.

Olmert to Stay Put - For Now

Olmert rejected Israeli Defense Minister Ehud Barak's demand Wednesday that he remove himself as prime minister -- at least until he is cleared of suspicions of bribery and money laundering.

"I will continue to function as prime minister," The Jerusalem Post quoted Olmert in his first public statement following Barak's press conference. 

"There are those who believe that every opening of an investigation requires a resignation. I don't think so, and I do not intend to resign," he said.

But Barak's Labor party has united behind him in calling for Olmert to step aside.

Both supporters on the left and opponents on the right are increasing the pressure on the prime minister.

"He should take a leave of absence until the decision is taken at the Ministry of Justice, whether to indict him, whether to press charges or not," Knesset member Colette Avital said.

Another Knesset member, Effie Eitam said, "If Ehud Olmert continues to be the prime minister of Israel, it will be a threat for the very existence and the very urgent problems Israel is standing in front of."

"The public and professional meaning of that is he has to resign immediately," Eitem concluded.

Foes Prepare for Olmert's Downfall

The Knesset's three biggest factions after Olmert's Kadima party -- Labor under Barak, the Likud party under Benjamin Netanyahu, and Eli Yishai's ultra-Orthodox Shas party -- all are making plans for the fall of the government and possible elections as early as November.

During his more than two years in office, Olmert has been a master of political survival.

But his legal woes could finally bring an end to his rocky time as Israel's leader.