Tobias Ellwood, whose brief includes anti-terrorism, performed mouth-to-mouth resuscitation on the officer in New Palace Yard within the grounds of Parliament.

Conservative MP Mr Ellwood, a former army officer, was pictured with a bloodied face after he was among those who tried to save the officer.

Sadly, the politician's efforts were ultimately in vain as the policeman later died.

The officer had been hurt after being stabbed by a suspected terrorist, who moments earlier had mowed down a number of pedestrians on Westminster Bridge.

Eyewitness Hugh Dickinson, a 21-year-old student from High Wycombe, posted a picture of the minister on Twitter, showing the minister bleeding, but saying "he looked to be fine".

Mr Dickinson said: "He had blood on his forehead as you can see but he wasn't bleeding profusely."

The Bournemouth East MP is a Foreign Office Minister, with the Middle East, Africa and counter terrorism listed among the areas within his brief.

Additional reporting from IRN