Pakistan president Pervez Musharraf's chances of avoiding impeachment appeared to dim yesterday as a key ruling party held firm against any deal that would protect him from criminal charges.

The country's foreign minister said Musharraf - who gave no public indication of resigning - needs to make up his mind in two days.

"Musharraf is running out of time," said Shah Mahmood Qureshi, a member of the main ruling Pakistan People's Party (PPP). "If he fails to decide to quit within the next two days, the impeachment process will take its course."

Allies and rivals of Musharraf have said ongoing back-channel talks could lead to the president's exit before an impeachment motion reaches parliament. Ruling coalition officials said yesterday that a draft of the impeachment charge sheet is awaiting approval from senior leaders.

Musharraf's spokesman has said the president is not resigning, but whether he decides to quit could depend on what his rivals are willing to offer - in particular if they will give him legal immunity and let him stay in the country.

But on such terms divisions have appeared in the ruling coalition, raising the likelihood of impeachment proceedings.

Sadiqul Farooq, a spokesman for the party of ex-prime minister Nawaz Sharif - who Musharraf ousted in a 1999 coup - said that legal guarantees were out of the question. Sharif's party is the second largest in the coalition and has said Musharraf should be tried for treason, which carries a maximum punishment of death.

"It will be in the interest of the country and the nation to make him an example in accordance with the constitution and the law," Farooq said.

That's a tougher tone than the line taken by the senior coalition member, the PPP. Information minister Sherry Rehman, a top PPP member, said the party "never indulges in the politics of revenge, as it wants a stable Pakistan and a sustainable democracy".

Musharraf dominated Pakistan for years after seizing power in a bloodless military coup, gaining favour from the US after supporting its war on terrorism. He gave up his dual role as army chief late last year, but by then he had grown very unpopular.

Many Pakistanis blamed rising violence in their country on his alliance with the US against the Taliban and al-Qaeda. His popularity hit new lows in 2007 when he ousted dozens of judges and imposed emergency rule in bids to avoid challenges to his rule.

His rivals came to power after February's parliamentary elections, largely sidelining him while pressuring him to step down.

The US has toed a publicly neutral line since the coalition declared its impeachment plans last week, as has Pakistan's army, Musharraf's former power base.

If he chooses not to quit, Musharraf could be the first president in Pakistan's turbulent history to be impeached.

Senator Mushahid Hussain, secretary-general of the pro-Musharraf Pakistan Muslim League party, has said the president's advisers were considering his options, with one being that Musharraf would resign but be allowed to stay "in peace" within the country.

Whether the president could safely stay in Pakistan is an open question. He is despised by Islamist militants and has already survived assassination attempts. Observers say a deal could send him to Turkey, but the US and the UK have also been suggested.