ISLAMABAD : Pakistan President Pervez Musharraf battled pressure on all sides Thursday as one former premier pledged to return from exile in September and another pushed him to quit as army chief.

Arch-enemy Nawaz Sharif, the man Musharraf ousted in a bloodless coup in 1999, said he would fly home on September 10 to challenge the president's plans to be re-elected in uniform by parliament.

Separately officials said Musharraf, whose position as a key US ally partly depends on his military role, had not yet decided whether to step down from the army to secure a possible power-sharing deal with Bhutto.

"On the 10th of September we will be landing at Islamabad," Sharif told reporters at a London press conference, adding that he wanted to "launch a decisive battle" against Musharraf.

Pakistan's Supreme Court, which has delivered a series of blows to Musharraf since his botched bid to sack its chief justice, ruled last week that Sharif could return from seven years in London and Saudi Arabia.

The conservative Sharif, 57, who served as premier between 1990 and 1993 and again from 1997 to 1999, condemned the proposed Bhutto deal as "bad for the country."

Pakistan's government said it was deciding on what action to take if Sharif returns -- amid speculation that it could either expel him immediately or arrest him on criminal charges that it says still stand against him.

"We will cross the bridge when we reach the bridge," Information Minister Muhammad Ali Durrani told AFP when asked about the two possibilities.

The minister said earlier that Musharraf had made "no decision yet" on whether he would stay in uniform following talks this week between the president's representatives and Bhutto.

Bhutto has said she needed to know by the weekend if Musharraf would agree to the pact that would also allow her to return from self-imposed exile on corruption charges, most likely to have a third term as premier.

Another major sticking point is the demand by Bhutto, whose Pakistan People's Party is the country's largest, that the president give up the power to dissolve the lower house of parliament, political sources said.

But she said in a series of interviews that most issues had been resolved with Musharraf, including a general amnesty for her, her husband and other lawmakers from her time in power.

Bhutto, a two-time premier from 1988 to 1990 and again from 1993 to 1996, said she may now return to Pakistan as early as September.

Musharraf's official spokesman said earlier that the president had rejected calls for him to make a snap decision on the deal, saying that he "never works under any pressure or ultimatum."

The president is already under intense pressure over the government's inability to quell extremist violence in tribal districts bordering Afghanistan and attacks in other cities.

He also came off worse in his feud with Pakistan's Chief Justice, Iftikhar Muhammad Chaudhry, whose suspension triggered a wave of protests across the country that eventually forced his reinstatement.

The violence and political chaos even led Musharraf to consider declaring a state of emergency earlier this month. General elections are due to be held by early 2008.

Also piling the pressure on the president is the Supreme Court's agreement Wednesday to hear a legal challenge against his role as army chief. The lawsuit was filed by the head of Pakistan's coalition of Islamist parties.

- AFP /ls