Olmert, under fire for his handling of last summer's war against Lebanese guerrillas, appeared to be quashing an incipient rebellion against him in the ranks of his Kadima Party _ at least for now.

On Wednesday, Foreign Minister Tzipi Livni, a party heavyweight, called on him to quit, and another top party figure, parliamentary coalition chief Avigdor Yitzhaki, resigned to protest Olmert's refusal to step down.

But other Kadima officials rallied around their beleaguered chief, no doubt mindful that a widespread mutiny could lead to early elections that could land the party on the skids. Polls indicate hawkish former Prime Minister Benjamin Netanyahu, leader of the opposition Likud Party, would win if new elections were held.

Olmert himself says he intends to stay on to remedy the severe flaws in decision-making and crisis management that a government war probe identified in a scathing report released on Monday. Olmert was singled out in the report for exceptional censure.

At an emergency Kadima meeting called after Livni's announcement Wednesday, Olmert said he would implement the war report's recommendations "down to the last detail."

"I'm personally in an uncomfortable position, but I'm over 60, and have had a lot of experience," spokesman Jacob Galanti quoted him as saying. "I've learned to take responsibility for my actions."

Israel's parliament interrupted its spring recess on Thursday to hold a special session to discuss the war probe.

Ahead of that session, Netanyahu for the first time added his voice to the chorus of calls demanding Olmert's resignation. Later, at parliament, he appealed for new elections.

"We must redress the primary flaw the report identifies _ the lack of a seasoned leadership, the lack of responsibility, the inability to make tough decisions and carry them out," he told a sparsely attended deliberation.

Olmert was present in the chamber, but was not scheduled to speak.

Hostilities erupted on July 12 when Hezbollah guerrillas crossed into Israel, killed three soldiers and captured two others.

In 34 days of fighting, nearly 160 Israelis died and nearly 4,000 Hezbollah rockets came crashing into northern Israel. More than 1,000 Lebanese civilians and combatants also died.

For many Israelis, the war was a failure because it didn't achieve the two main goals Olmert set _ returning the soldiers and crushing Hezbollah. And while the guerrilla group was pushed away from Israel's northern border, Israeli intelligence officials have warned that Hezbollah has replenished its depleted store of missiles with help from its Syrian and Iranian backers.

Opinion polls released Wednesday show two out of three Israelis want Olmert out now.

In defecting from Olmert's camp, Livni _ a popular figure in Kadima _ told the prime minister he had lost the public's support, and said she considered herself the rightful successor to lead Kadima.

"I told him that resignation would be the right thing for him to do," Livni told reporters. "I haven't worked and am not working to topple the prime minister. That's a decision he'll have to make."

But Vice Premier Shimon Peres, emerging from the Kadima meeting late Wednesday, said the party backed Olmert in his decision not to resign.

"The prime minister received here unprecedented support," Peres told reporters.

Only three Kadima officials have publicly broken with Olmert _ Livni, Yitzhaki and a minor lawmaker, Marina Solodkin.

Reuven Hazan, a political scientist at the Hebrew University of Jerusalem, said Livni's challenge would have been worse had she threatened to resign or bring down the government.

"We see a ball rolling, but a ball that could have taken on a lot of momentum today has slowed down," he said.

The turnout by Olmert's opponents at the rally in Tel Aviv on Thursday, Hazan said, could determine whether the momentum against Olmert grows or fizzles out.

Lawmakers Effie Eitam, a hawk, and Yossi Beilin, a dove, set aside their deep political differences to team up in a joint newspaper column on Thursday, demanding a shakeup at the top. They predicted hundreds of thousands of Israelis would show up in Tel Aviv to call for a new leader.

"Both of us are convinced Olmert has to go home because of his great failure during the second Lebanon war," they wrote in the column that appeared in the Maariv daily, under the headline, "Come Protest."

Alon Davidi and 34 other protesters started marching to Tel Aviv two days ago from the southern town of Sderot, 70 kilometers (45 miles) away.

"We want as many people as possible to come to the square and say, 'Ehud Olmert go home,' '(Defense Minister) Amir Peretz go home,"' Davidi told Army Radio.

Sderot is Peretz's hometown, and the frequent target of Palestinian rocket attacks.