The latest appeal comes four days after the supreme court dismissed a number of legal challenges by the opposition. The court upheld Musharraf's eligibility to stand in Saturday's poll.
"Pakistan needs a military leader who can control both civil and possible military extremism"
Creative_person01, Islamabad, Pakistan
Send us your views
But his opponents want him to resign his military position beforehand. They say that the election should not be by the current, outgoing parliament but by a new assembly formed after a general election.
"The COAS [chief of army staff] should be declared ineligible and until a decision on the petition, the election should be stayed," Ausaf Ali said, shortly before he filed the petition on behalf of Ahmad.
Ahmad is a former supreme court judge who resigned in 2000 rather than swear allegiance to Musharraf, an army general who seized power in a coup in 1999.
Pakistani opposition members of parliament backed by hundreds of flag-waving supporters marched on parliament on Tuesday to stage a mass resignation in protest at Musharraf's re-election bid.
Imran Khan, the cricketer-turned-politician and one of the leaders of the anti-Musharraf Alliance for the Restoration of Democracy, said: "This is the first step to discredit the election process."
The MPs and about 600 supporters, most of whom waved the flags of the Jamaat-e-Islami party, marched from a parliamentary apartment building in Islamabad to the national assembly.
They shouted slogans such as: "This is the end of your show - Go Musharraf, Go!" and "A friend of America is a traitor".
Musharraf is expected to win as his allies dominate the current national and federal parliaments that are conducting the vote - but opponents hope that the more than 80 planned resignations will erode its legitimacy.