JERUSALEM — Israeli Prime Minister Ariel Sharon is playing coalition hardball as the drumbeat of Palestinian terror resumes.

Two days after firing four Cabinet ministers from the fervently religious Shas Party for failing to support the government's emergency economic plan, Sharon said Wednesday he would not change his mind even though he was left with a slim coalition of 60 votes in the 120-member Knesset. Sixty-one votes would be needed to topple the government.

His stance is earning him points among some Israelis, who long have accused Shas of pursuing narrow self-interest.

But others question the wisdom of Sharon's firings, aware that Shas support has been crucial to the survival of more than one Israeli government.

If Sharon is to stay in power, he will have to work closely with his left-wing Labor Party partners to make sure they don't leave his coalition. On the right, Sharon's arch-rival Benjamin Netanyahu is waiting for the prime minister to slip so he can challenge him in new elections.

The political instability facing the Sharon government comes as another Palestinian bomber struck Wednesday night, killing at least three Israelis and wounding more than 40 in Rishon le-Zion.

Police were looking for a car thought to have dropped off the suicide bomber a short time before the explosion, Israel Radio said.

A senior police officer said the bomber had a "European" appearance, including dyed blond hair, Ha'aretz reported.

The attack took place on the city's major pedestrian mall.

It was the second bombing in Rishon le-Zion in recent weeks. Fifteen Israelis were killed and more than 60 wounded in a suicide bombing at a pool hall May 7.

"This was another cowardly act of terror committed by Palestinian terrorists who have once again resorted to their murderous deeds," said David Baker, an official in the Prime Minister's Office. "Israel will not buckle under in the face of terror and we will use whatever measures are needed to root it out."

A massive Israeli invasion of the West Bank, undertaken in response to an escalating wave of Palestinian terrorism in March, had provided a brief respite from terror attacks.

There were several attacks this week, however. A bomb in the coastal city of Netanya on Sunday killed three people and wounded dozens. On Monday, a suicide bomber detonated explosives at a traffic junction in northern Israel, killing only himself.

The week was tumultuous on the political front as well. Two days after Sharon suffered a humiliating defeat when his emergency economic package was rejected, the Knesset overwhelmingly approved the same package Wednesday.

With support from Likud and Labor legislators who had not taken part in Monday's previous vote, the Knesset on Wednesday gave preliminary approval to the bill by a 65-26 vote, with seven abstentions.

The bill, which calls for budget cuts of $2.7 billion and raises taxes to fund the increased defense spending necessitated by the intifada, now faces at least one more vote before final passage.

Fervently religious legislators from the Shas Party, who opposed the bill on Monday, absented themselves from Wednesday's vote.

After firing Shas and United Torah Judaism ministers and deputy ministers for opposing the bill Monday, Sharon remained firm Wednesday, saying the dismissals would not be rescinded.

A fifth Shas minister who is not a legislator resigned.

The dismissals took effect midnight Wednesday.

Opinion polls published Wednesday showed wide public support for Sharon's move. At least one poll gave him a 70 percent approval rating.

After announcing the firings late Monday night, Sharon reportedly instructed aides to break off all contact with Shas officials, including refusing to take their phone calls.

He also convened his political advisers to discuss the unfolding coalition crisis.

Without Shas, which has 17 Knesset seats, and UTJ, which has five, Sharon's coalition shrunk from 82 to 60 of the Knesset's 120 seats.

Even so, Sharon's government was not in immediate danger of collapse, because 61 votes are required to bring down a government in a no-confidence vote.

Just the same, Sharon may have to depend more than ever on his uneasy partnership with the Labor Party.

Political observers are questioning how far Sharon can go in depending on Labor, which is suffering its own internal strains.

In a sign of those strains, only 12 of the 24 Labor legislators voted for the budget bill Monday. One, Nawaf Masalha, voted against, and the remaining 11 members voted with their feet — by not being present for the vote.

The guiding hand behind the split in Labor's vote was said to belong to Knesset member Haim Ramon, a potential rival to Binyamin Ben-Eliezer for party leadership — and an advocate for withdrawing from the unity government.

The day after Monday's vote, Ben-Eliezer blasted those Labor members who opposed the bill.

Slamming the conference table at a party meeting, Ben-Eliezer declared, "the circus is over."

Some commentators hailed Sharon for standing up to the powerful Shas Party where other prime ministers, including his Labor predecessor, Ehud Barak, had capitulated.

Sharon has a number of options before him, they said, including bringing the secular Shinui Party, which has six Knesset seats, into the coalition.

Shinui leader Yosef Lapid said his party believes the budget bill is "bad and faulty," but it abstained during Wednesday's vote "in order to send a silent sign of appreciation" to Sharon.

"For the first time, a prime minister has stood up to the blackmail" of the fervently Orthodox parties," Lapid said.

Lapid also said Wednesday his party would join the coalition if the government does away with subsidies to large families and drafts fervently religious yeshiva students.

Shas legislator Yair Peretz predicted early elections if Sharon brings Shinui into the government.

In the meantime, the political scene was charged with speculation over whether Shas would join the opposition or return to the fold.