LIB DEM peer Lord Carlile called on PM David Cameron yesterday to bolster Britain’s draconian anti-terror powers in response to the alleged involvement of a British national in the killing of US journalist James Foley.

The freelancer was decapitated in a filmed execution by a man thought to be a British member of the extremist group Islamic State (Isis).

Hundreds of Britons are believed to have travelled to the region to fight, among them the man known as “John” from London who apparently carried out the on-screen beheading.