Pakistan's former prime minister, Nawaz Sharif, has said his Pakistan Muslim League (PML-N) party will not participate in the planned elections on 8 January, and that no one should benefit from Benazir Bhutto's killing.
But her assassination leaves him as far and away the most powerful opposition politician, and his behaviour over the coming days could be crucial to the way events play out. His party is particularly strong in the politically all-important province of Punjab.
Mr Sharif, ousted by Pervez Musharraf in a 1999 coup, finally returned from exile last month. But although he has been central to his party's campaign, the country's election commission had already ruled that he was not eligible to stand as a candidate. Mr Sharif has suggested he could not work with Mr Musharraf and it is difficult to see how the two bitter rivals could compromise. But the PML-N, in opposition for years, is equally desperate to seize power.
General Ashfaq Kayani, the head of the armed services, is one of the most powerful people in Pakistan. The former head of the powerful Interservices Intelligence Service (ISI) was sworn in as head of the armed services last month when Mr Musharraf stood down from the post and became a civilian president.
General Kayani is considered a West-friendly career soldier. He has spent time in Washington, where he is well-thought of. The avid golfer has kept a deliberately low profile but in the aftermath of the state of emergency declared last month, a flurry of rumours suggested that General Kayani had led a coup against Mr Musharraf.
They were not true but they highlighted General Kayani's central role in the military-political establishment. Could the military yet turn on Mr Musharraf? If the military considered him unable to keep order, some believe he could be vulnerable to being pushed aside and the army declaring martial law.
Atizaz Ahsan, the prominent lawyer and human rights campaigner, has been named as a possible successor to Ms Bhutto as head of the Pakistan People's Party, (PPP). But the party has always ben led by a Bhutto and some observers fear it could disintegrate into factions.Reuse content