Spooks are “very close” to identifying the apparently English jihadist who beheaded a US journalist, Britain’s ambassador to Washington said yesterday.

Mi5 and MI6 have been piecing together intelligence in a bid to track down the identity of the Islamic State killer dubbed “jihadi John.”

They are analysing horrific video footage of the brutal murder of journalist James Foley which was posted by the extremist group last week.

Ambassador Sir Peter Westmacott told US news network CNN that Britain is on the brink of establishing who he is.

“We are very close to identifying who this guy is,” he told its State of the Union programme.

Government officials refused to comment on the specific claims.

But a Home Office spokesman said: “The police, security services and Border Force are actively working to identify, detect and disrupt terrorist threats, including from British fighters attempting to return to Britain.”