MI5 has concluded that there is no easy way to identify those who become involved in terrorism in Britain, according to a classified internal research document on radicalisation seen by the Guardian.

The sophisticated analysis, based on hundreds of case studies by the security service, says there is no single pathway to violent extremism.

It concludes that it is not possible to draw up a typical profile of the "British terrorist" as most are "demographically unremarkable" and simply reflect the communities in which they live.

The "restricted" MI5 report takes apart many of the common stereotypes about those involved in British terrorism.

They are mostly British nationals, not illegal immigrants and, far from being Islamist fundamentalists, most are religious novices.

. . . .Far from being religious zealots, a large number of those involved in terrorism do not practise their faith regularly. Many lack religious literacy and could actually be regarded as religious novices. Very few have been brought up in strongly religious households, and there is a higher than average proportion of converts. Some are involved in drug-taking, drinking alcohol and visiting prostitutes. MI5 says there is evidence that a well-established religious identity actually protects against violent radicalisation.

. . . .Crucially, the research has revealed that those who become terrorists "are a diverse collection of individuals, fitting no single demographic profile, nor do they all follow a typical pathway to violent extremism".

. . . .The MI5 authors stress that the most pressing current threat is from Islamist extremist groups who justify the use of violence "in defence of Islam", but that there are also violent extremists involved in non-Islamist movements.