Israel could begin withdrawing from parts of the West Bank and Gaza Strip in about six months, a confidant of Prime Minister Ariel Sharon said in an interview published Monday, a day after tens of thousands of protesters demonstrated against a possible pullback.

The comment by Vice Premier Ehud Olmert (search) was the first time an Israeli official has given a timeline for a unilateral withdrawal. Sharon has said he will carry out the plan, including removing some Israeli settlements in the West Bank and Gaza, if efforts to reach a peace deal fail.

Olmert, whose comments are often seen as trial balloons for the prime minister, told The Jerusalem Post that Israel could begin taking unilateral steps in as little as six months.

"In my estimation, by the month of the June, our preparations for major unilateral moves will be complete ... and this plan, including withdrawal from certain settlements, will begin to be implemented in the second half of this year," Olmert was quoted as saying.

Sharon formally unveiled his go-it-alone plan last month. He has not released details, but said the Palestinians would receive far less territory than in a negotiated settlement.

At a news conference in Jerusalem on Sunday, Sharon said he remains committed to the U.S.-backed "road map" peace plan, which is to lead to a Palestinian state. In that case, Sharon said, "we will not be able to keep all our Jewish communities" in the West Bank and Gaza.

About 230,000 settlers live in 150 settlements, and Sharon reportedly would dismantle 17 isolated settlements as part of his plan.

Israeli media have reported that Maj. Gen. Giora Eiland (search), who is to oversee the disengagement plan, has already ordered government ministries to begin preparations for the pullback.

Such talk has infuriated the Palestinians, who say a deal cannot be imposed. However, the prime minister has also angered settlers, who oppose any pullback.

About 120,000 settlers and their backers gathered in Tel Aviv on Sunday night to protest the plans by Sharon, once their greatest champion.

The demonstrators heard ministers from Sharon's own Cabinet heap criticism on the prime minister. Some politicians threatened to leave the ruling coalition of he carries out his plans.

Housing Minister Effi Eitam of the pro-settler National Religious Party (search) accused the prime minister of weakness.

"In the battlefield there is no disengagement plan, you know that would be running away," he said.

"We won't dismantle settlements and we won't expel Jews," Eitam said to the cheers of the crowd. "We will not be a party to dismantling settlements."

The settlers and their supporters believe they have a God-given right to live anywhere in the biblical Land of Israel, which includes the West Bank. However, Palestinians say the settlements encroach on land they want for a future state.

Protester Micha Cohen, 35, said he had come to the demonstration with his two small children "because for us the struggle is for their future ... we see settlements as important places that should not be evacuated."

Many of the protesters were teenagers and high school children bused in by their schools and youth movements.

"Sharon can't ignore such a big group of people," said settler leader Pinchas Wallerstein. "There is no doubt that it will be much harder to dismantle settlements after this."

Meanwhile, Sharon's office announced Monday that an Israeli man has been arrested for allegedly driving a Palestinian suicide bomber to an attack site last month — the first time a Jew is accused of assisting a bomber.

Ofer Shwartzboim, 39, of the Jewish settlement of Oranit, apparently was not aware that the person sitting in the back seat of his taxi was a suicide bomber. The bomber blew up in a bus stop near Tel Aviv, killing four Israelis.

Shwartzboim told interrogators he knew the bomber and his accomplice had entered the country illegally, the prime minister's office's statement said. He told investigators that he often drove illegal Palestinian workers into Israel.

Israel forbids assisting illegal Palestinian workers, partly because they could be attackers.