Yet another competitor is an Islamic revivalist movement, Tablighi Jamaat, rooted in south Asia but active in Africa and Europe, especially Britain.

ECONOMIST: Global Muslim networks

Philips, recruited in the U.S. by Tablighi Jamaat, went to school in Saudi Arabia, was made a proselytization official by the Saudi Air Force.

CENTERFORSECURITYPOLICY: Waller testimony on terrorist infiltration

It was during this time that Vinas became disillusioned with the apolitical worldview of the Tablighi Jamaat and attracted to a more "hard-line" interpretation of Islam.

CNN: The radicalization of an all-American kid

But the spokesman for Tablighi Jamaat said it was wrong to suggest the money should go into the NHS as there "has never been a request for public funding" for the Abbey Mills project.

BBC: The Downing Street website

Many take advantage of Tablighi Jamaat's benign reputation.

CENTERFORSECURITYPOLICY: Tablighi Jamaat: Jihad's stealthy legions

After joining Tablighi Jamaat groups at a local mosque or Islamic center and doing a few local dawa (proselytism) missions, Tablighi officials invite star recruits to the Tablighi center in Raiwind, Pakistan, for four months of additional missionary training.

CENTERFORSECURITYPOLICY: Tablighi Jamaat: Jihad's stealthy legions