Asif Ali Zardari, widower of the murdered former Pakistan prime minister Benazir Bhutto, has purged almost all of his wife’s top advisers from her party, including her political secretary and closest friend, who cradled her as she died.

Bhutto was killed by an assassin’s bullet as she waved to supporters at an election rally in Rawalpindi on December 27 last year.

Shortly after her death Zardari took control of her Pakistan People’s party (PPP) and led it to an election victory, invoking Bhutto’s memory and capitalising on the public grief that followed her death.

He is expected to become Pakistan’s president this week in an election that will formally acknowledge him as the country’s most powerful man.

It will be an extraordinary reversal of fortune for a man who spent 11 years in jail on corruption and other charges and is widely blamed for Bhutto’s two governments being dismissed in 1990 and 1996.

Last week the party’s members of the National Assembly pledged their loyalty to him in an atmosphere of competitive sycophancy. But behind the scenes, party stalwarts whom Bhutto had relied upon are angry at the way her closest aides have been humiliated and alarmed that her political legacy is being betrayed.

They are outraged that some of Zardari’s aides have blamed Bhutto’s most trusted advisers for her death, accusing them of failing to protect her from the assassins who killed her in a sniper and suicide bomb attack.

Their target was Naheed Khan, Bhutto’s devoted political secretary and inseparable friend for more than 20 years. Khan, who has been sidelined since the assassination, was sitting next to her leader in a bullet-proof Land Cruiser when Bhutto was shot while waving to supporters through the sun-roof. Khan cradled Bhutto’s head on her lap before realising she was dead.

Last month Zulfiqar Mirza, the Sindh home minister and a close aide of Zardari, claimed Khan had been in charge of Bhutto’s security on the day she was killed and that she had declined his offer of volunteer guards. Khan’s husband, Safdar Abbasi, another Bhutto adviser, had argued with her police detail and dismissed them, he alleged.

When Zardari failed to disown his friend’s comments, another Bhutto loyalist, Makhdoom Amin Fahim, stepped in, dismissed his allegations and said they were the work of the “new faces” controlling the PPP.

Last week Khan and Abbasi denied the allegations. “Mr Zardari’s friends are saying we did not protect her. But we are political people. Three of us were in the car and none of us was looking after her security. Mr Rehman Malik [now interior minister] was the security adviser. Second in charge was Zulfiqar Mirza. I don’t know why these people are being rewarded,” said Khan.

Abbasi and Khan said their concern was that the party remains true to Bhutto’s vision. They and several other former members of Bhutto’s staff said that Zardari had wasted the first six months in government. They believed their former leader would have hit the ground running.

“We were with Bibi [Benazir] through all the trials and tribulations and we loved our work with her,” said Khan, who added that Zardari was cut off from the masses. “Party workers are disillusioned and don’t know what to do. They have no access to him or to people working for him.”

Another Bhutto adviser, Nawab Yusuf Talpur, a former agriculture minister, said only four or five members of her team had made the transition to the Zardari camp. “Most of the people trusted by Bibi are not trusted by him. Benazir had a vision and had the capacity to hold this party together . . . Her legacy is not being handled in the way we expected,” Talpur said.

Despite growing concern at his leadership, Zardari’s chances of becoming president improved last week after the army signalled that it would stay out of the contest. Speculation that the army might interfere had grown after medical records revealed that Zardari had suffered mental problems after his years in jail and exile.

Further questions about Zardari’s suitability for the office were raised after the Swiss government said it was releasing some of his bank accounts containing $60m. “How can he explain that kind of money?” asked one Bhutto aide.

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