Benazir Bhutto's party was to discuss a successor to the slain Pakistani opposition leader on Sunday and decide whether to contest an election due in little over a week, as controversy swirled about exactly how she died.
Bhutto's assassination in a suicide attack on Thursday has stoked violence and thrown into doubt the January 8 elections, deepening the crisis in the important US ally against terrorism as it struggles to emerge from military rule.
Anger against President Pervez Musharraf burns strongly among Bhutto's supporters and since her killing sporadic violence has erupted, raising concerns about stability in the nuclear-armed nation.
The death toll from the violence has reached 44.
Bhutto's Pakistan People's Party has dismissed the government claim she was killed by Al-Qaeda, saying Musharraf's embattled administration was trying to cover up its failure to protect her.
Without the charismatic Bhutto, 54, her party is in disarray.
Bhutto's 19-year-old son, Bilawal, is to read her will on Sunday but the Oxford law student is seen as too young to lead a dynasty whose history is entwined with that of Pakistan.
The choice of a successor more likely lies between Bhutto's husband, Asif Ali Zardari, and her top aide, Makhdoom Amin Fahim.
"Everybody in the party knows that they have to stick to the legacy of Bhutto and without that legacy, they are nobody," said Najam Sethi, editor of the Daily Times.
The party leadership, due to meet in Bhutto's home town of Naudero in southern Pakistan, must also decide whether to contest the election if it goes ahead.
Former prime minister Nawaz Sharif's opposition party has said it would boycott the vote and has been trying to convince Bhutto's PPP to do likewise.
So far the government has not announced any decision to call off or postpone the vote, but the Election Commission says it is planning an emergency meeting on Monday.
Although US President George W Bush, like several other world leaders, has urged Pakistanis to hold the election, a White House spokesman said it was up to Pakistan's authorities to determine the timing.
Washington had encouraged Bhutto, relatively liberal by Pakistan's standards and an opponent of Islamic militancy. She returned home from self-imposed exile in October, hoping to become prime minister for the third time.
Her death wrecked US hopes of a power-sharing deal between her and Musharraf, who took power in a military coup in 1999 but left the army last month to become a civilian president.
When asked by the BBC on Saturday if he wanted to take over the party leadership, Bhutto's husband replied, "It depends on the party and it depends on the will."
Zardari can ooze charm, and gained respect for enduring eight years in jail before being released without being convicted. However, political foes accuse him of corruption and some PPP loyalists blame him for tainting the Bhutto name.
Many PPP leaders are from Bhutto's land-owning feudal class, yet the party also has a big following among the uneducated poor yearning for democracy.
A close aide who prepared Bhutto's body for burial dismissed as "ludicrous" a government theory she died after hitting her head on a sunroof during the suicide attack. A party spokesman said she was shot in the head.
Interior Ministry spokesman Javed Iqbal Cheema said the government's version was based on a medical report and other evidence collected from the scene of the attack.
"If the People's Party's leadership wants, her body can be exhumed and post-mortemed. They are most welcome," he added.
The PPP has said the government must also show hard evidence Al-Qaeda is to blame. The Al-Qaeda-linked militants who were accused have denied any role in the killing. A spokesman for militant leader Baitullah Mehsud said "We don't strike women."
Other militants, however, had issued threats against Bhutto when she returned in October, and her triumphal entry into Karachi then was met with a suicide bomb attack that killed at least 139 people.
US House of Representatives Speaker Nancy Pelosi said on Saturday that Washington should address "troubling questions" about Pakistan's probe of Bhutto's assassination and its cooperation in fighting terrorism before extending any more aid.
Democrat Pelosi called for an international investigation into Bhutto's death.