Benazir Bhutto claimed three senior allies of Pakistan's president General Musharraf were out to kill her

Benazir Bhutto claimed three senior allies of Pakistan's president General Musharraf were out to kill her in a secret email to Foreign Secretary David Miliband written weeks before her death.

Astonishingly, one of them is a leading intelligence officer who was officially responsible for protecting Miss Bhutto from an assassination.

The second is a prominent Pakistani figure, one of whose family members was allegedly murdered by a militant group run by Miss Bhutto's brother. The third is a well-known chief minister in Pakistan who is a long-standing opponent of Miss Bhutto.

Miss Bhutto told Mr Miliband she was convinced that the three were determined to assassinate her on her return to the country and pleaded with him to put pressure on the Pakistan government to stop them.

The disclosure is bound to lead to questions as to whether the Foreign Office did enough to safeguard Miss Bhutto.

Her return was organised in close co-ordination with the UK and US governments, which saw her as the best hope of restoring democracy in Pakistan while preventing it from falling into the hands of Islamic extremists.

The email concerning the three alleged would-be killers identified by Miss Bhutto emerged as rival political factions in Pakistan continued to dispute the details surrounding her assassination.

The Pakistan government said she was killed by Al Qaeda, but her People's Party dismissed that as "a pack of lies" and insisted General Musharraf's regime was implicated.

Wajid Shamsul Hasan, Pakistan's former High Commissioner to the UK and a British-based adviser to Miss Bhutto, said: "She sent an email to the Foreign Office before she returned to Pakistan naming certain people.

"In the email, she said, 'The following persons are planning to murder me and if any harm comes to me they should be held responsible.'"

Miss Bhutto wrote her prophetic email to Mr Miliband in September, shortly after she met him to discuss her return to Pakistan. She named the same three individuals in a letter to General Musharraf in October.

The Mail on Sunday has been informed of the names but has decided not to publish them.

One is a senior intelligence officer and retired army officer who worked for Pakistan's sinister Inter Services Intelligence spy agency, which has close links to the Taliban and has been involved in drug smuggling and political assassinations. He allegedly directed two Islamic terrorist groups and reportedly once boasted that he could pay money to hired killers to assassinate anyone who posed a threat to Musharraf's regime.

He was given another senior intelligence post by Musharraf after his bid to become a senior overseas diplomat for Pakistan failed when the host country refused to let him in because of his past activities.

He was also linked to Omar Sheikh, the former British public schoolboy convicted of kidnapping US journalist Daniel Pearl, who was murdered in 2002 by having his throat cut and being decapitated by Islamic terrorists.

The second individual named by Miss Bhutto is well known in Pakistani political circles and has been involved in a vicious family feud with her for decades.

One of his relatives was said to have been murdered by the militant Al Zulfiqar group run by Miss Bhutto's brother, Murtaza. The organisation was set up to avenge the execution of Miss Bhutto's father Zulfiqar Bhutto by ex-Pakistan dictator Zia ul Haq.

The third individual is a chief minister who has repeatedly denounced Miss Bhutto - and faced political annihilation if she won the elections scheduled for next week. He made an outspoken attack on her only hours before her death.

A senior source said: "She knew the risk she was taking when she decided to go back but also took the precaution of informing the British Government of the names of those she thought presented the biggest danger to her.

"She hoped Mr Miliband would use his influence with General Musharraf to remove certain people from positions where they were able to plot against her. She gave the same names to General Musharraf but she knew there was only a limited possibility of any action being taken.

"She had to rely on Mr Musharraf and countries such as Britain and America, who supported her return and have close connections with Mr Musharraf's government, to take her concerns seriously.

"Events have shown she was right to be worried. If any of the three people she named turn out to have been involved in this assassination, there will be serious repercussions."

The Mail on Sunday has also learned that after an earlier attempt to assassinate her in October, the Foreign Office told Miss Bhutto to stop making wild allegations against Musharraf - or face greater danger.

A Foreign Office spokesman said: "Miss Bhutto had a series of meetings with the Foreign Secretary and other officials. She raised her concerns about particular people and we raised them in turn with the authorities in Pakistan and asked them to put in place more strict security measures to protect her."