The ruling Pakistan Muslim League-Q party confirmed on Tuesday that Musharraf signed the nomination papers for his candidacy, with 17 legislators, including Shaukat Aziz, the prime minister, endorsing him.
"We have the required votes to ensure his success," Mushahid Hussain, the party's secretary-general, said.
The same day, opposition fears that Musharraf could declare a state of emergency if he did not retain the presidential office, were fuelled afresh by a government lawyer's remarks.
Malik Mohammed Qayyum, the attorney-general, told a supreme court bench that Musharraf would remain the chief of the army if he was not re-elected.
No martial law
Qayyum denied that any moves towards authoritarianism were being considered.
"There will be no martial law. There will be no emergency," he said.
That failed to mollify members of the opposition coalition, the target of a crackdown that has landed at least 100 party leaders and members in preventive custody.
"Pakistan needs a military leader who can control both civil and possible military extremism"
Creative_person01, Islamabad, Pakistan
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Musharraf, a close US ally in its so-called war on terror, who seized power in a 1999 coup, has pledged to step down as military chief and restore civilian rule if legislators approve a fresh mandate on October 6.
But he has seen his popularity and power erode since his failed effort to fire the supreme court's chief justice earlier this year.
The opposition says he cannot run while still in uniform.
A judge asked Qayyum what would happen if Musharraf was not re-elected.
Qayyum said Musharraf's position was if "I am not elected, then I will remain chief of army staff".
He said Musharraf could do so under a law that allows him to hold both positions at the same time and suggested he could retain the powerful military post as long as he remains president.
The law expires at the end of 2007 although his presidential term ends on November 15.
Parliamentary elections are to follow by January.
Meanwhile in Washington, Benazir Bhutto, the former Pakistan prime minister, has criticised US support for Musharraf, saying it makes the fight against extremists operating along the Pakistani-Afghan border more difficult.
Bhutto, who plans to return next month from self-exile to challenge him, said on Tuesday that Musharraf has tried to convince the world that only he stands in the way of extremists hoping to overrun nuclear-armed Pakistan.
|Bhutto addressed the Middle East Institute|
in Washington DC on Tuesday [AFP]
"In fact, military rule is the cause of the anarchic situation in Pakistan," she said.
Bhutto said that under Musharraf, Pakistan had become "the petri dish of the international extremist movement" and that only a new government with broad support could root out Muslim militancy.
Fighting the Taliban and al-Qaeda "requires a national effort that can only flow from legitimate elections", she said at the Middle East Institute on Washington's Capitol Hill.
Bhutto also said that if returned to power, she would allow UN inspectors but not Western powers to question Abdul Qadeer Khan, the father of Pakistan's nuclear bomb.
Musharraf has refused to grant any access to US officials eager to question the nuclear scientist since he admitted to passing atomic secrets to Libya, Iran and North Korea in a televised confession in February 2004.
Speaking on her party's political programme, Bhutto, who is planning to return home from self-exile next month, said that the Pakistan People's Party was nominating Makhdoom Amin Fahim, one of its two vice chairmen, to stand against Musharraf in the polls.
"We are doing this because we want to put ourselves in a better position to have more options," she said.
"The issue of general Musharraf's legitimacy is foremost in the minds of Pakistani people."
Bhutto said that if the supreme court rejects his nomination but still allows the election to go ahead, any official candidate has a chance.
"So as a precaution, we are filing our candidate," she said.