RAMALLAH - The two feuding Palestinian factions risk sliding into a constitutional limbo if they do not strike some form of agreement ahead of a key election deadline.

As the Islamist Hamas and secular Fatah trade invective and accusations over the scuppering of a long-delayed reconciliation deal announced by Egypt last week, the cutoff date for calling a new vote is fast approaching.

Palestinian Basic Law mandates that a new general election must be called at least three months before the end of the sitting parliament's mandate, a deadline which falls on October 25.

Palestinian president Mahmud "Abbas must announce a date for elections before October 25 so as not to create a constitutional void," said Samir Awad, a professor of international relations at the West Bank's Birzeit University.

The constitutional limbo risks cementing the Palestinian rift into what Walid al-Mudallal, a political scientist at Gaza's Islamic University, said would be a "really serious division."

Less than two weeks before the key date, the divisions between the two camps appear as deep as ever.

Just days after Egypt announced that the two main Palestinian factions would sign a long-delayed reconciliation deal at the end of the month, the leaders of the two camps took to the airwaves on Sunday to hurl insults at each other.

Abbas, who heads Fatah, said Hamas was delaying reconciliation in order to solidify its "coup" in Gaza, while Hamas chief Khaled Meshaal called the president's legitimacy into question.

Abbas's four-year term expired last January but Fatah has cited provisions in the constitution that require presidential and parliamentary elections to be held together to justify his remaining in office.

Senior Fatah official Mohammed Dahlan said that, in the absence of a signed unity agreement postponing elections to June, his party would request that Abbas hold elections in January, raising the possibility that the voting could be confined to the West Bank.

"If there is no agreement, there will be elections and Hamas will have to decide on the subject," Dahlan told a press conference in Ramallah.

"The two camps are moving further and further away," said Hani al-Masri, a political analyst in Ramallah, the political capital of the Israeli-occupied West Bank, where Abbas's government exercises limited authority.

A possible compromise could be a new proposal by Egypt that would see Fatah and Hamas separately sign an agreement by October 15, with the other Palestinian factions signing up by October 20.

Under this scenario, Hamas and Fatah would not have to sign the accord in the same room, thereby saving face, and Abbas would call presidential and legislative elections for June 2010, a senior Fatah source told AFP.

Fatah has already agreed to the proposal and Egypt was waiting for an answer from the Islamists, according to senior Fatah officials.

Yasser Abed Rabbo, another senior Fatah official speaking at the same event with Dahlan, said the Egyptians had asked Abbas to issue a decree on October 24 in which he would set a June date for the elections.

"But if the package is not accepted as a whole, including the date for the elections on June 28, we will go back to the (original schedule) and announce elections on January 25," Abed Rabbo said.

Hamas-Fatah tensions date back to the start of limited Palestinian self-rule in the mid-1990s when Fatah strongmen cracked down on Islamist activists.

They went up a notch in January 2006, when in a surprise election rout, Hamas beat the dominant Fatah to grab more than half the seats in parliament.

And in June 2007 they boiled over into a week of deadly street clashes and ended with Hamas routing pro-Fatah forces from Gaza, splitting the Palestinians into two camps, with the Western-backed Fatah in charge of the West Bank and Western-shunned Hamas ruling the coastal strip.