LAHORE, Pakistan Ousted Prime Minister Nawaz Sharif on Monday registered to run in Pakistan's parliamentary elections next month, while President Gen. Pervez Musharraf prepared to step down as army chief and be sworn in as its civilian leader.
A day after returning from exile, Sharif signed his nomination papers at a court in the eastern city of Lahore. Supporters packed into the courtroom chanted "Prime Minister Nawaz Sharif!"
However, he maintained a threat to boycott the Jan. 8 parliamentary vote and said that, even if he took part and won, he would not lead any government under Musharraf.
Asked by an Associated Press reporter whether he would actually contest the seat in his hometown, Sharif replied: "I have submitted my papers. ... Let's see where we end up."
Sharif's surprise return to Pakistan on Sunday poses a major threat to Musharraf, the man who ousted him in a 1999 coup and became a key U.S. ally against international terrorism.
Sharif and other opposition leaders are threatening to boycott the parliamentary elections a step that would wreck Musharraf's plans for a controlled return to democracy that the West hopes will produce a moderate government committed to countering Islamic extremism.
But even if they take part in the vote, Sharif's harsh rhetoric suggests Musharraf faces a bumpy ride as he tries to prolong his eight-years in power.
The army spokesman said Musharraf would "most probably" be sworn in Thursday as a civilian head of state meeting a key demand of his domestic critics and international sponsors.
"So he is going to take off his uniform a day before that," spokesman Maj. Gen. Waheed Arshad told AP Television News.
A spokesman for Benazir Bhutto, another former premier seeking to return to power, said ending direct military rule would be a "major" step forward. If Musharraf makes more concessions, "then the window for negotiations can be reopened," spokesman Farhatullah Babar said.
Bhutto, who filed nomination papers in two constituencies Monday, had been in talks with Musharraf before he declared a state of emergency Nov. 3.
She expressed skepticism that the opposition can agree on a boycott.
"We are ready to talk to any moderate party to find common ground and to continue our struggle for democracy," she said in Larkana, where supporters showered her in rose petals. "We are concerned that elections will be rigged but we don't want to leave the arena or the field empty."
But Sharif insisted Musharraf would have to reinstate Supreme Court judges purged under the emergency and obtain their approval before he would be "acceptable" to his party.
Musharraf has accused the court of triggering the crisis by interfering with the government as well as the security forces' efforts to fight rising Islamic militancy.
The judges were about to rule on the legality of Musharraf's victory in an October presidential election when they were swept away under the emergency.
Sharif also said curbs on the media and the emergency should be lifted before the polls, which he said were being rigged to favor the ruling party.
"We don't want to boycott elections, but if you push someone to the wall ... what options are left?" he said, adding that he was not a "candidate for prime ministership under Pervez Musharraf."
Both Sharif and Bhutto are barred from serving again as prime minister under constitutional changes pushed through by Musharraf. However, the next parliament or Musharraf, with his emergency powers, could make alterations as part of whatever new power setup emerges from the turmoil.
Officials also suggest that Sharif will be disqualified from the election because of a conviction handed down in the wake of Musharraf's coup.
Sharif arrived from Saudi Arabia, where has spent most of his eight years in exile.
Musharraf swiftly booted Sharif back to the kingdom when he flew into Pakistan in September. But the Pakistani leader appears to have lost the support of the Saudi royal family, who provided a special flight to carry Sharif and a host of his relatives home.
Analysts suggest Saudi Arabia was unhappy that Sharif, a conservative leader with whom it has developed close relations, was being excluded from Pakistan's power struggle while Bhutto, a pro-U.S. leader with family ties to regional rival Iran, was taking part.
Bhutto returned after her own long exile in October. Her massive homecoming parade through Karachi showed that her secular, socially moderate party remains well-organized. But it was torn by a suicide bombing that killed about 150 people and issued an ugly reminder of the threat posed by rising Islamic militancy.
The army said Monday it had killed another 15 militants in fighting in the Swat Valley, a former tourist destination about 100 miles north of the capital, Islamabad.
Sharif appeared bent on emulating Bhutto on Sunday, riding atop a truck for hours through the packed streets of Lahore amid fireworks and cheering supporters.
"Musharraf has taken this country to the brink of destruction," Sharif had shouted to the crowd before dawn. "Should not such elections be boycotted?" he asked, prompting chants of "Boycott, boycott!"
Musharraf has moved to ease the crackdown since the retooled Supreme Court approved his re-election last week.Most of the thousands of opponents, human rights activists and lawyers detained since Nov. 3 have been released. Yet Musharraf has so far resisted pressure to lift the emergency and restore the constitution.
Associated Press writers Slobodan Lekic in Lahore, Ashraf Khan in Larkana, Sadaqat Jan and Stephen Graham in Islamabad, and AP Television News producer Andrew Drake in Rawalpindi contributed to this report.