Like other British radicals, Bakri has long been regarded as little more than a loudmouth by parts of the British media and the intelligence services. With his sidekicks Anjem Choudhury, leader of ALM, and Hassan Butt, Bakri has been seen more as an irritant than a threat.

The authorities may have been lulled into a false sense of security because Bakri, who acts as ALM’s spiritual leader, insisted that his followers obey a “covenant of security” which, while encouraging terror abroad, forbade them from carrying out attacks in Britain.

Seven days after the September 11 attacks Bakri issued a fatwa (religious ruling) containing a death threat against President Pervez Musharraf of Pakistan. Last week, in an address to the nation about the London bombings, Musharraf referred to it with indignation.

“There are extremist organisations in the United Kingdom — Hizb ut-Tahrir and al-Muhajiroun — who operate with full impunity,” he said. “They had the audacity to pass an edict against my life . . . I know that they also give sermons of hate, anger and violence. Therefore I would like to say that there is a lot to be done by Pakistan and may I suggest that there is a lot to be done in England also.”

M J Gohel of the Asia-Pacific Institute agrees. “Al-Muhajiroun is involved in the softening up process, preparing and indoctrinating people so that they are susceptible when the Al-Qaeda recruiter comes along,” he said.

Last November Bakri announced that ALM was disbanding. Three months later he said the “covenant of security” was no longer in force. Experts note that the London bombings followed four months later.

A Sunday Times investigation shows that long before the bombings ALM supporters had built a reputation for violence and religious intolerance. Among its members are:

More worrying is the number of ALM members associated with violence abroad. One journalist who visited an ALM safe house in Lahore before the authorities closed it said that recruits from Britain referred to Indians as “subhumans” and were violently opposed to homosexuals and Jews.

The house was run by Sajeel Shahid, known as Abu Ibrahim, who holds a computer science degree from Manchester. In January he was freed after three months in jail and expelled from Pakistan for his alleged support of Al-Qaeda.

Back in London, Shahid told an Arabic newspaper that he was a close friend of Mohammed Naeem Noor Khan, a computer expert now in a Pakistani prison, who planned to launch a bombing campaign in London. The plot was foiled when the London cell was arrested last year.

One of those who passed through the house is Bilal Mohammed from Birmingham, who in 2001 blew himself up in an attack on an Indian barracks in Srinagar, Kashmir.

Others in Pakistan with close links to ALM include Zeeshan Siddiqui, from Hounslow, west London, who is thought to have been in contact with the London suicide bombers. He was arrested in Pakistan in May. Siddiqui was also a close friend of Asif Hanif, one of two British-born suicide bombers who attacked Mike’s Place in Tel Aviv in 2003, killing three and injuring 60. Hanif, too, was an ALM member.