JERUSALEM – Tens of thousands of Jewish settlers and supporters demonstrated yesterday against Prime Minister Sharon’s plan to evacuate all settlements from Gaza and four West Bank enclaves in a rally held against a backdrop of assassination threats and warnings of civil war.

The withdrawal plan has upset the Israeli political scene since it was announced last year, turning Mr. Sharon’s backers into opponents and detractors into supporters.

Skeptical Palestinians believe the whole plan is a trick to annex large parts of the West Bank to Israel.

Most of those filling Jerusalem to protest the proposed pullout were Orthodox Jews – many of them teenagers. A huge banner behind the stage set the theme: “Disengagement tears the people apart.” Many waved blue and white Israeli flags.

Though organizers pledged to prevent incitement to violence, some signs said the head of Mr. Sharon’s disengagement committee would “not be forgiven,” and others read, “A time to love, a time to hate,” quoting the biblical Book of Ecclesiastes.

At a Cabinet meeting yesterday, Mr. Sharon warned of statements of “grave incitement” that were “directing toward a civil war.”

“There are not enough voices being heard among the Cabinet on this subject,” Mr. Sharon complained.

The issue of incitement has been especially sensitive in Israel since the November 4, 1995, assassination of Prime Minister Rabin by an ultranationalist Jew opposed to Rabin’s policy favoring territorial concessions to the Palestinian Arabs in exchange for peace.

Some Israeli commentators have compared the current atmosphere to the vitriolic period that preceded Rabin’s death. Mainstream settler leaders rejected Mr. Sharon’s statement as an attempt to paint all of them with the extremist brush.

“We are completely against violence or threats of violence,” Settlers Council spokesman Josh Hasten said. “These blanket statements unjustly put an entire group into a category.”

Israel’s minority Orthodox Jews revere the West Bank as part of the biblical Jewish homeland.

“This is the land of Israel, not the land of Ishmael,” ancestor of Islam, Rabbi Shlomo Aviner said to cheers from the crowd.

Polls show that the secular Jewish majority favors steps to distance Israel from the Palestinian Arabs, including an exit from Gaza and removal of some West Bank settlements.

Opposition to Mr. Sharon’s plan comes from his traditional constituency. For decades, Mr. Sharon was the prime mover behind creation and expansion of Jewish settlements.

His change of heart shocked supporters and left traditional opponents skeptical. In the months that have followed his first pronouncement at the end of last year, Mr. Sharon has tried to convince both sides of his sincerity.

Mr. Sharon has argued that the Jewish presence in Gaza has become untenable, with about 8,000 Jews in 21 settlements living along 1.3 million Palestinian Arabs.

Mr. Sharon said pulling out of Gaza would help Israel solidify its hold on parts of the West Bank, where most of the 240,000 settlers live, and would pre-empt international peace initiatives he feels would be unfavorable to Israel.

Mr. Sharon refuses to coordinate the pullout with Palestinian officials, charging that Yasser Arafat’s administration is responsible for four years of violence.

Palestinian Arabs counter that Israeli military moves lead to violence, and they believe Mr. Sharon’s plan amounts to a West Bank land grab to prevent them from forming a state.

Mr. Sharon’s domestic opposition is just as formidable. Twice he has lost internal Likud Party votes on his plan by wide margins, but he insists he will carry it out regardless.

Demonstrators gathering carried signs featuring a picture of Mr. Sharon labeled, “The Dictator.”

Peace negotiations broke down after renewed violence broke out in 2000, and now Mr. Sharon, a vocal opponent of Rabin’s proposals at the time, is offering withdrawals with nothing in return from the Palestinians, enraging the same ultranationalists who had opposed Rabin.

Last week, a group of prominent Israeli hard-liners published a call to Israeli soldiers to disobey orders to carry out the withdrawal. Settler leaders said Friday Mr. Sharon had no mandate to carry out the withdrawal; calling the plan a “Nazi act” and warning it could lead to civil war.