Israel's defence minister said Wednesday he would use his considerable power to topple the coalition government if Prime Minister Ehud Olmert does not step aside to face corruption allegations.

The comments by Ehud Barak increased the growing pressure on Olmert to resign in the wake of a U.S. businessman's court testimony that painted Olmert as a money-hungry politician with a love for luxury.

Olmert has denied any wrongdoing and said he would resign only if he is indicted.

At a news conference in Jerusalem, Barak said that in light of the criminal investigation, he did not think Olmert could focus on peace efforts and the country's pressing security needs.

"I don't think the prime minister can at the same time lead the government and handle his own affairs. Therefore, acting out of concern for the good of the country … I believe the prime minister must disconnect himself from the day-to-day running of the government," Barak said.

There was no immediate reaction from Olmert, but Olmert aide Tal Zilberstein said earlier Wednesday that the prime minister "doesn't have any intention to resign or to step down temporarily, even if Barak asks him to."

Olmert's spokesman, Mark Regev, said the prime minister was continuing his daily schedule. "It's business as usual," Regev said.

Election could be soon

Barak said Olmert could suspend himself, resign or even go on vacation. He promised to co-operate with a new leader from Olmert's Kadima Party, but vowed to force new elections if Olmert doesn't step aside.

"If Kadima doesn't act and this parliament doesn't see another government that is to our liking, we will act to set an agreed-upon date for early elections," he said. He said the date would be "soon."

Although Barak stopped short of setting a firm deadline, his comments have made it difficult for Olmert to stay in power. If Labour withdraws from the coalition, Olmert will lose his parliamentary majority and the country will be forced to hold new elections.

Israel's popular foreign minister, Tzipi Livni, would become caretaker prime minister if Olmert steps down. The party then could try to form a new government, and if that effort fails, elections would likely ensue.

Israeli prosecutors are investigating tens of thousands of dollars in donations collected by Olmert before he became prime minister in 2006. Prosecutors suspect he may have violated campaign finance laws or accepted bribes.

On Tuesday, the key witness in the case, U.S. businessman Morris Talansky, testified that he personally gave Olmert $150,000 over 15 years, often in cash-stuffed envelopes.

Olmert, who denies wrongdoing, says the funds were legal contributions.