RAMALLAH, West Bank (AP) – Palestinian President Mahmoud Abbas said Thursday he will call a national referendum on accepting a Palestinian state alongside Israel if Hamas does not agree to the idea within 10 days.

Abbas’ surprise announcement was a political gamble that could either help resolve the Palestinians’ internal deadlock or lead them into a deeper crisis with the militant Hamas group.

Such a vote would effectively ask Palestinians to give implicit recognition to Israel by accepting a Palestinian state on land occupied by Israel in 1967. Approval of the 18-point plan would provide a way out of the impasse over acceptance of Israel, which has led to an international freeze on aid to the Hamas-led government.

Hamas officials were divided over the idea of a referendum, with several giving their blessing, but others dismissing it as an attempt to undercut the Hamas-led government.

A referendum, which Palestinian pollsters expect to pass, could provide cover for the militants to moderate without appearing to succumb to Western pressure. Such a vote could also renew pressure on Israel to return to the negotiating table rather than imposing borders on the Palestinians.

However, Amar Duaik, director of the Palestinian election commission, said calling a referendum might not be easy. He said the parliament would have to pass a referendum law or Abbas would have to issue a presidential decree.

“If there is no agreement (between Hamas and Fatah), I expect to have troubles and differences,” Duaik said.

In Gaza, meanwhile, violence erupted again between Fatah and Hamas forces. A police officer was killed in the shootout in Gaza City, and the two sides blamed each other for starting it.

In the past week, 10 people have been killed in the Hamas-Fatah clashes, leading to concerns of a civil war. The talks in Ramallah were designed to defuse the crisis.

Abbas’ proposal came as Israeli Prime Minister Ehud Olmert returned from a trip to Washington, where he presented President Bush with a West Bank pullout plan. Olmert said if there is no breakthrough in long-stalled peace efforts in the coming months, Israel would withdraw from much of the West Bank, solidify its control of large settlement blocs and unilaterally draw its border with the Palestinians.

The Palestinians reject Olmert’s unilateral plan, and Abbas’ announcement Thursday appeared part of a hurried effort to show the world there is a willing Palestinian partner for negotiations with Israel.

Abbas said that if 10 days of dialogue between Hamas and his Fatah movement did not lead to a joint political platform, he would call a referendum 40 days after that. The dialogue began Thursday.

The referendum would ask Palestinians to either accept or reject a document that had been drafted earlier this month by senior Palestinian militants jailed in Israel. The five-page document calls for a Palestinian state in the West Bank, Gaza and east Jerusalem, the areas Israel captured in the 1967 Mideast War.

The draft was negotiated by leading prisoners from Hamas and Fatah over the period of four weeks at Israel’s Hadarim Prison, where top Fatah prisoner Marwan Barghouti is being held.

The talks took place in a wing for Palestinian security prisoners, where 120 inmates are held, said Barghouti’s lawyer, Khader Shkirat. After the factions’ political leaders gave their blessing, Barghouti drafted an outline that was revised in the negotiations, Shkirat said. Many of the sessions took place in the prison yard.

Hamas is pledged to Israel’s destruction and has rejected international demands that it recognize the Jewish state or renounce violence. The group appeared to soften its position since taking power in March, but has refused to explicitly give up its demands for an Islamic state in all of historic Palestine, which includes Israel.

It was not clear whether Abbas had briefed Hamas before the announcement on the referendum. Some Hamas officials said they had been taken by surprise, but said they support the idea.

“Returning to the people is one of the most important principles in democracy,” said Parliament Speaker Abdel Aziz Duaik, of Hamas, who added that the prisoners’ document was a good basis for dialogue.

However, Hamas legislator Mushir al-Masri said that a referendum was a “coup against the democratic choice” of the Palestinians who swept Hamas into power in January parliament elections.

The smaller Islamic Jihad group, which also rejects the existence of Israel, said it opposed the referendum proposal.

Israeli officials declined to comment.

Speaking to reporters after his speech, Abbas said he did not mean his proposal to be a game of brinkmanship, but said a national consensus was needed urgently.

“The situation is getting more dangerous. The whole nation is in danger. We can’t wait for the rest of our lives,” he said.

Yasser Abed Rabbo, a close adviser to Abbas, said Hamas and the other Palestinian groups had to make a choice, “either to accept the prisoners’ document as it is or to go to a referendum.”

“Both solutions are satisfactory and can get us out of the impasse,” he said. “All that the international community needs is there in this document and we think that they will accept it.”

Palestinian pollster Nader Said of Bir Zeit University in Ramallah said he expected the referendum to pass because most Palestinians support a two-state solution.

“I think it has a very good chance to pass, I think it will get high support,” he said, estimating it could pass by as much as two-thirds.

Abbas made his proposal at the start of a national conference of Palestinian factions intended to hammer out a joint Palestinian platform. The meeting was held by video conference between the West Bank city of Ramallah and the parliament building in Gaza City.

Abbas, usually a restrained speaker, spoke with unusual enthusiasm, repeatedly gesturing as he implored the gathered leaders to work together.

He said Hamas backed the proposal to call for a state in what are known as the 1967 borders.

“All the Palestinians, from Hamas to the Communists, all of us agree we want a Palestinian state on the 1967 borders,” he said. “This is what we have, we cannot talk about dreams.”

In an earlier speech to the gathering, Prime Minister Ismail Haniyeh of Hamas said his group would not moderate its positions to get the economic boycott imposed by the West after Hamas’ election victory lifted.

“I want to assure here, and make it clear for all parties, that the Palestinian government and the Palestinian people will not make any compromise that harms the Palestinian goals and rights,” he said.

Abbas has said that Hamas must moderate to regain international support for the Palestinian cause.

“The Arab countries are waiting for this realistic position, to work in harmony, to push the Palestinian cause ahead. They cannot do anything for the Palestinian cause if the (Palestinians) are rejecting everything,” he said.

Both Abbas and Haniyeh called for an end to internal tensions that have repeatedly exploded into violence in recent days, leaving at least nine people dead.

“We are not going to engage in a Palestinian-Palestinian conflict,” Haniyeh said.