A Pakistani Supreme Court judge hearing new petitions against President Pervez Musharraf's re-election bid has pulled out from a nine-member bench of judges.
Gen Musharraf's election plans are illegal, critics say
Judge Sardar Raza Khan's decision to withdraw will delay the hearing. The court will now have to name a new panel of judges.
Two rival candidates for Saturday's election have filed fresh petitions against Gen Musharraf's candidacy.
They say he is not eligible to stand while also remaining head of the army.
Last Friday the Supreme Court dismissed a number of petitions, in a move seen as a major victory for the president.
Judge Sardar Raza Khan was one of the judges who had dissented from the ruling that allowed Gen Musharraf to contest Saturday's election.
"I don't think I should sit on this bench as I have expressed my opinion on this previous case," he was quoted telling the court by the AFP news agency.
"This case is similar to that case, there is no difference."
The head judge of the panel, Javed Iqbal told the news agency that they would "make every effort to reconstitute the bench".
The fresh petitions against Gen Musharraf's candidature have been filed by rival candidates, former Supreme Court judge Wajihuddin Ahmad and Makhdoom Amin Fahim, parliamentary leader of the Pakistan People's Party of Benazir Bhutto.
Gen Musharraf will resign as head of the army if he wins presidential elections on Saturday, his lawyers say.
Opposition parties say his candidacy is illegal and that he has broken previous promises to resign as army chief.
Scores of opposition MPs resigned from Pakistan's national parliament and provincial assemblies in protest at Saturday's presidential election.
They insist that President Pervez Musharraf is ineligible to stand.
Correspondents say that the resignations make it even more certain that Gen Musharraf will win the vote.
Members who resigned from the assemblies on Tuesday were drawn mainly from an alliance of Islamic parties, the MMA, and the PML-N party of former Prime Minister Nawaz Sharif.
Ms Bhutto's Pakistan People's Party the country's biggest party, is not taking part in the boycott.