Regular raids, arrests, the uncovering of alleged plots - there have been many apparent success stories for police over the past couple of years in the war on terror.

But although more than 500 arrests have been made under the Anti-Terrorism Act since the 11 September attacks, few of those arrests have led to charges.
The Home Office said last night that 548 arrests had been made between 11 September 2001 and 16 March this year, and 91 people had since been charged under the Anti-Terrorism Act. A spokeswoman said it was unclear how many of those arrested had been charged under other laws.