A crucial Knesset vote yesterday sealed into law a plan to uproot all residents of Jewish towns in Gaza and some in the West Bank for the first time since Israelis settled there after the 1967 war.

The convincing majority vote in favor of Prime Minister Sharon’s initiative known as the “disengagement plan” was seen as a victory for the man who once was described as the “father of the settlements.” It also redrew the political map in ways that might erase alliances that existed in Israel’s public life since before the establishment of the state in 1948.

Most significant was what was described by many as a split in the right-wing coalition that since Mr. Sharon’s victory in the February 2001 election has given the majority Knesset support necessary to keep his government in power.

Finance Minister Benjamin Netanyahu, who harbors ambitions of returning to the top leadership position, headed a dissenting bloc among the majority party, Likud.

The bloc voted for Mr. Sharon’s plan but demanded a national referendum before its implementation. Mr. Netanyahu said that if such a referendum were not announced within 14 days, he and his four major supporters would leave the government. Mr. Sharon has adamantly opposed a referendum.

The looming threat of a split in Likud and in the ruling coalition did not dampen the sense of victory in Mr. Sharon’s camp and the prime minister held out hope that he could carry the plan and avoid a breakup in Likud, the party he helped create and lead to its first victory in 1977.

Mr. Sharon’s supporters pointed out that the ultimatum posed by Mr. Netanyahu’s camp came after the vote, in which he and his supporters joined the majority of 67 Knesset members who voted for the plan. Forty-five of the 120-member Parliament opposed, including almost half of the Likud legislators, and 7 abstained.

“In Israel, a crisis postponed may be crisis averted,” Mr. Sharon’s adviser and veteran Likud member Zalman Shoval told The New York Sun.

The Left and core supporters of Mr. Sharon argue that a national decision by referendum, which has never been tried in Israel, is alien to the political culture, based on a parliamentary democracy. They are also concerned that it would take a long time to arrange, which might postpone the implementation of the disengagement plan.

Leaders of the settlement movement hope their political mobilization abilities would help them overcome the vast majority of Israelis who, according to polls, support Mr. Sharon’s plan. Other settlers oppose the disengagement plan but are also concerned about the specter of settlers taking arms against the army in case of a forced evacuation. A referendum, they argue, would give the soldiers credibility and would assure smooth implementation if the plan is approved by the people.

“We are not trying to get anyone out of office or to unseat anyone,” Mr. Netanyahu told reporters at the Knesset after the vote. “We are trying to bring a referendum to the people because otherwise there will be a huge split here. We’re trying to give unity a chance, unity of the Likud and unity of the people.”

Supporters of Mr. Sharon said that if the group around Mr. Netanyahu chooses to split from the coalition, they could rely on a new coalition based on the dovish Labor party. The head of the Labor party, Shimon Peres, has indicated that he would support such a unity government in order to save the disengagement plan, which Labor and the left support.

The plan, which was approved on the ninth anniversary of the assassination of Prime Minister Rabin, according to the Jewish calendar, raised fears that fanatics would try to assassinate Mr. Sharon as well. Rabbis made pronouncements that for many Israelis sounded eerily similar to those made on the eve of Mr. Rabin’s assassination, a point made clear by Defense Minister Shaul Mofaz at a memorial service yesterday.

Prior to the vote, Mr. Sharon addressed the Knesset in a stark and dramatic speech.

“This is an hour of destiny for the state of Israel,” he said, describing the evacuation of Jewish settlements as “the hardest of decisions.” Addressing the settlers, he said they have “developed a messianic complex.”

Immediately after the vote, Mr. Sharon made clear his intentions of dealing with those who opposed his plan. Two Likud members who had served as cabinet ministers, Michael Ratson and Uzi Landau, were summoned to the prime minister’s office after the vote, in which they joined the opposition, and were immediately fired.

A spokesman for the State Department, Adam Ereli, said yesterday: “The plan, as presented by Prime Minister Sharon, is a good opportunity and it is one that helps both parties achieve what we’re all working towards.”

The United Nations’ special coordinator for the Middle East, Terje Roed- Larsen, supported the plan on the eve of the Knesset vote, calling it a “first major move” toward implementation of the roadmap.

Palestinian Arabs were cautious. A Hamas spokesman, Moushir al-Masri, however, said that the vote is a victory for the “resistance” forces in Gaza, who by their actions pushed Israel out.

In America, the national security adviser, Condoleezza Rice, expressed support for the unilateral nature of the plan, as Mr. Sharon refuses to deal with Yasser Arafat. “People are going to have to draw together and say to Yasser Arafat, ‘All right, the game is up,'” Ms. Rice told the American Israel Public Affairs Committee. “Land is now being returned to the Palestinian people,” she added. “You said that’s what you wanted all these years. Now it is time to step aside.”

Senator Kerry’s top foreign policy adviser, Richard Holbrooke, who also addressed Aipac, said that the Democratic presidential candidate agrees with President Bush on disengagement and in not negotiating with Mr. Arafat. Mr. Kerry, he added, would be more involved than Mr. Bush and would send a special envoy to the Middle East.

Mr. Arafat was the subject of new rumors yesterday, as his health seemed to continue to deteriorate. According to a story on the Web site of the Israeli daily Maariv, his most recent trouble was described by doctors as a complication resulting from the 75-year-old Mr. Arafat’s decision to carry on a fast required of Muslims during the month of Ramadan.

Yesterday, Mr. Arafat broke the fast at the urging of his doctors, who found that he was suffering from a gallstone, the Associated Press reported. According to Maariv, he is expected to be moved to a Ramallah hospital for the removal of stones in his kidneys.