RAMALLAH, West Bank (AP) – Palestinian leader Mahmoud Abbas will ask Hamas to form the next Palestinian government after the Islamic militants swept parliament elections, and the defeated Fatah Party will serve in the opposition, a senior Fatah legislator said Thursday, after meeting with Abbas.

A Hamas-only government, without Fatah as a moderating force, is sure to throw Mideast peacemaking into turmoil.

The Islamic militants, who carried out dozens of suicide bombings and seek Israel’s destruction, have said they oppose peace talks and will not disarm. Israel and the United States have said they will not deal with Hamas.

Earlier Thursday, the top Hamas leader, Khaled Mashaal, told Abbas his group is ready for a political partnership.

However, Fatah does not want to join a Hamas government, said Fatah legislator Saeb Erekat. “We will be a loyal opposition and rebuild the party,” Erekat said, after meeting with Abbas.

Erekat said Abbas will ask Hamas to form the next government.

Abbas was elected separately a year ago and remains president. However, the Palestinian leader, who favors peace talks with Israel, has said he would resign if he could no longer pursue his agenda.

Aides said he planned a major speech Thursday night, after final results are announced by the Central Election Commission at 7 p.m.(1700 gmt).

Acknowledging the Hamas victory, Palestinian Prime Minister Ahmed Qureia and his Cabinet ministers resigned Thursday, hours before official results from Wednesday’s vote were released.

“This is the choice of the people. It should be respected,” Qureia said. “If it’s true, then the president should ask Hamas to form a new government.” The Cabinet remained in office in caretaker capacity.

Hamas supporters streamed into the streets to celebrate victory. In Rafah in the southern Gaza Strip, Hamas loyalists shot in the air and handed out candies. Others honked horns and waved Hamas flags from car windows.

Reactions to the Hamas victory streamed in from around the world. Italian Premier Silvio Berlusconi, according to news reports, called it a “very, very, very bad result.”

Benita Ferrero-Waldner, the EU external relations commissioner, said Hamas must be “ready to work for peace” with Israel if it joins the Palestinian government.

U.N. Secretary-General Kofi Annan congratulated the Palestinian people on the peaceful legislative elections, which he said was an important step toward a Palestinian state.

Hamas capitalized on widespread discontent with Fatah’s corruption and ineffectiveness. Much of its campaign focused on internal Palestinian issues, while playing down the conflict with Israel.

Before the election, Hamas had suggested it would be content as a junior partner in the next government, thus avoiding a decision on its relationship with Israel.

Throughout the campaign, leaders sent mixed signals, hinting they could be open to some sort of accommodation with Israel. Its apparent victory will now force it to take a clearer position on key issues, including whether to abandon its violent ideology.

Mushir al-Masri, a Hamas candidate who won election in the northern Gaza Strip, said peace talks and recognition of Israel are “not on our agenda” but the group is ready for a partnership, presumably with Abbas.

Israeli officials declined comment, but senior security officials gathered Thursday to discuss the results. Acting Prime Minister Ehud Olmert scheduled talks with senior officials later in the day.

Olmert said Wednesday, before Hamas claimed victory, that Israel cannot trust a Palestinian leadership in which the Islamic group has a role. “Israel can’t accept a situation in which Hamas, in its present form as a terror group calling for the destruction of Israel, will be part of the Palestinian Authority without disarming,” Olmert said in a statement issued by his office.

Wednesday’s election marked the first time Hamas has contested a legislative vote, and leading the Cabinet could give it significant powers. The Cabinet holds wide control over security forces, finance and other government functions, though Abbas has retained power mainly through tradition and political leverage.

Palestinian election officials confirmed early Thursday that Hamas had won a large majority of the seats up for grabs in electoral districts in the West Bank and Gaza. Half the seats in Wednesday’s parliament vote were chosen on a national list and the other half by districts. While the national voting appeared to be close, election officials said Hamas had won a large majority in the district races. Hamas apparently took advantage of divisions in Fatah; the long-ruling party fielded multiple candidates in many districts, allowing the Islamic group to capitalize.

Initial exit polls had forecast a slight edge for Fatah, with Hamas coming in a strong second. The polls predicted that neither party would have a majority and would have to rely on smaller parties to form a coalition. However, on Thursday morning, Hamas officials said the group had won up to 75 seats, giving it a solid majority in the 132-member parliament.

Officials in Fatah conceded that Hamas had won at least 70 seats, or enough to rule alone. They spoke on condition of anonymity because counting in some districts was continuing.

Palestinian pollsters were at a loss to explain the discrepancy between the exit polls. Many voters said they had been afraid to admit to pollsters they had supported Hamas, fearing retribution. Also, the errors appeared especially glaring in the district races, where smaller numbers of voters were polled.

Following the exit polls showing them winning, Fatah loyalists fired rifles out of car windows, sounded their horns and waved the yellow flag of their movement in celebration.

Palestinian legislator Hanan Ashrawi, who apparently was re-elected on a moderate platform, said the Hamas victory was a dramatic turning point for the Palestinians. She said she is concerned the militants will now impose their fundamentalist social agenda and lead the Palestinians into international isolation.

She said Fatah’s corruption, Israel’s tough measures and international indifference to the plight of the Palestinians were to blame for Hamas’ strong showing. Washington miscalculated in pushing for the vote, as part of its pro-democracy campaign in the Arab world, she said. “The Americans insisted on having the election now, so they have to respect the results of the election, as we all do,” she said.

Israel has repeatedly asked Abbas to force Hamas and other militant groups to disarm but Abbas has refused, warning such an act could cause civil war. Hamas has committed dozens of suicide bombings against Israel.

U.S. President George W. Bush told The Wall Street Journal in aninterview Wednesday that the United States will not deal with Hamas until it renounces its position calling for the destruction of Israel.

Turnout for Wednesday’s vote was heavy, with nearly 78 percent of 1.3 million eligible voters casting ballots. The polling stations were heavily guarded, and there were no reports of major violence.

International observers, led by former U.S. President Jimmy Carter and former Swedish Prime Minister Carl Bildt, reported no major problems with fraud.