The prime minister has defended the security services amid criticisms they failed to stop Mohammed Emwazi, known as ‘Jihadi John’, from joining Islamic State in Syria.
David Cameron said the security services made “incredibly difficult judgements” on the UK’s behalf.
His comments came after it emerged Emwazi was known to authorities.
The PM said he would not comment on specific cases but urged the public to back the security services.
Emwazi, who is in his mid-20s, first appeared in a video last August, when he apparently killed the US journalist James Foley.
He was later thought to have been pictured in the videos of the beheadings of British aid worker David Haines, US journalist Steven Sotloff, British taxi driver Alan Henning, and American aid worker Abdul-Rahman Kassig, also known as Peter. ‘Incredibly difficult judgements’
BBC security correspondent Frank Gardner told Radio 4’s Today programme there were questions about how “someone on a terror watch list, somebody of real concern, was able to slip out of this country and turn up in Syria like that unhindered”.
UK-based advocacy group Cage has suggested that MI5 may have contributed to the radicalisation of Emwazi.
Downing Street said the claim was “completely reprehensible”, while London mayor Boris Johnson described Cage’s comments as “an apology for terror”.
Mr Cameron defended the security services, praising the work of “these extraordinary men and women”.
He said: “I meet with them regularly, I ask them searching questions about what they do and in my almost five years’ experience as prime minister, I think they are incredibly impressive, hard-working, dedicated, courageous and effective at protecting our country.
“All of the time, they are having to make incredibly difficult judgements and I think basically they make very good judgements on our behalf, and I think whilst we are in the middle of this vast effort to make sure British citizens are safe, the most important thing is to get behind them.”
Mr Cameron went on to say the security services’ “dedication and work has saved us from plots on the streets of the UK that could have done us immense damage” within the last few months.
He said he was satisfied there was effective scrutiny of the work they do. Emwazi has appeared in videos dressed in a black robe with a black balaclava covering all but his eyes and top of his nose.
Speaking with a British accent, he taunted Western powers before holding his knife to the hostages’ necks, appearing to start cutting before the film stopped. The victims’ decapitated bodies were then shown.
Earlier this month, a video in which the Japanese journalist Kenji Goto appeared to be beheaded featured the militant.
Hostages released by IS said he was one of three British jihadists guarding Westerners abducted by the group in Syria.
Families have given mixed reactions to the militant being named, with the mother of Mr Foley saying she forgave Emwazi while Mr Haines’s daughter, Bethany, said she wanted to see “a bullet between his eyes”.
Emwazi is believed to have travelled to Syria around 2013 and later joined IS, which has declared the creation of a “caliphate” in the large swathes of Syria and neighbouring Iraq it controls.
British police have not commented on the identity of the militant known as “Jihadi John”, citing ongoing inquiries. (BBC)