“Under our government system, if the prime minister is gone, the Cabinet is gone,” Jahangir Badar, a senior party leader, told a news conference. “We will meet our coalition partners, then the party will meet tomorrow, then we will announce what we will do.”

Gilani and other party members have insisted that only Parliament can disqualify the prime minister, but it appeared that the PPP would have to bow to the judiciary in this case. Observers said that a new prime minister would face the same pressure from the judiciary over the Swiss cases.

“Whoever becomes prime minister will be told by the court to write the letter. So it has to be someone who will resist writing the letter,” said Chaudhry Faisal Hussain, a lawyer. “It’s a question of the survival of the president.”

The Pakistan Peoples Party has claimed that the president has constitutional immunity from prosecution both in Pakistan and abroad, so the letter also would be unconstitutional.

Many believe that the only way out of the political and constitutional impasse is through early elections, which seem increasingly likely to be called before the next scheduled vote in February 2013, perhaps as soon as this fall.

In Punjab, where many areas are without electricity for 12-18 hours a day, the violent protests have attacked the houses of several parliamentarians from the Pakistan Peoples Party, accusing the party of indifference while the energy crisis mounts. PPP leaders suspect that the main opposition party, the Pakistan Muslim League-N, is inciting the violence in Punjab, home to over half the country’s 180 million people. Demonstrators also have burned and smashed up private property, cars, police stations and government offices.

The legal intrigue in Islamabad also has ensnared the judiciary itself, with the son of the chief justice alleged to have taken bribes from a wealthy businessman in return for promises to fix cases pending against him. Supporters of the chief justice suspect that the government or the military were behind the attempt to tarnish its image.