Pakistan's Supreme Court on Monday began hearing 10 petitions against President Pervez Musharraf in proceedings that would determine the political future of the embattled leader.

The petitions filed by the religious political party Jamaat-e-Islami, the liberal Tehrik-e-Insaf (Movement for Justice) party and several civil society organizations and individuals have urged the top court to disqualify Musharraf as a candidate in the upcoming presidential election.

A nine-member panel of judges headed by Rana Bhagwandas is hearing the petitions, which have also challenged Musharraf having two offices as head of the government and the military at the same time, arguing that the constitution does not allow it.

"These cases are very important as they are going to determine the future course of the country," Bhagwandas said as the hearings opened.

Musharraf has been at loggerheads with the Supreme Court since February when he suspended Chief Justice Iftikhar Chaudhry after the court, under Chaudhry's leadership, gave rulings against the government, a rarity under military leaders in Pakistan.

Chaudhry was reinstated in July after a countrywide campaign for independence of the judiciary by lawyers and opposition activists.

Musharraf, who seized power in a bloodless coup in 1999, intends to seek a new five-year term as president from the parliament in October.

The opposition has vowed to resist his re-election, and the All Parties Democratic Movement, an alliance of 32 opposition groups, announced Sunday that its members would resign soon after Musharraf's nomination papers were accepted.

Dozens of opposition workers were gathered Monday outside the Supreme Court. They chanted, "Go, Musharraf, go," as hundreds of security personnel guarded the building.

Musharraf, a key US ally in the war against terrorism, is currently beleaguered by a sharp slump in his popularity and inability to control rising militancy in the country.

He has successfully sidelined his main opponent and former premier Nawaz Sharif by deporting him last week to Saudi Arabia as he arrived at Islamabad's airport after seven years of exile.

The move challenged a ruling by the top court that said Sharif should be allowed to return.

Another opposition leader and former prime minister, Benazir Bhutto, has also announced her planned return to Pakistan from exile on Oct 18.

She has been engaged in an inconclusive dialogue with Musharraf for months on a power-sharing deal under which Bhutto's party would facilitate the president's re-election in return for sharing power in the national legislature. One of the sticking points in the negotiations has reportedly been Bhutto's demand that Musharraf give up his post as army chief.