Boris Johnson has suggested a convicted murderer who helped fight off a terrorist on London Bridge should be honoured for his bravery.

Serving prisoner Steven Gallant took on Usman Khan as he embarked on a killing spree armed with two knives and wearing a fake suicide vest on November 29.

Jack Merritt and Saskia Jones died in the attack, which started at a prisoner rehabilitation event in Fishmongers’ Hall that Gallant was attending, having been allowed out on licence for the first time since he was sentenced for killing Barrie Jackson in Hull in 2005 alongside another man.

The 42-year-old, who was jailed for a minimum of 17 years, helped restrain Khan on London Bridge before the terrorist was shot dead by police.

Harrowing footage shows Gallant, wearing a purple top with sleeves rolled up, and two other men, running on to the bridge after Khan and tackling him to the ground.

The prime minister said he was “lost in admiration” of Gallant’s “gallantry” and said it should be “recognised in the proper way”.

Gallant’s local MP Karl Turner asked Johnson at prime minister’s questions: “In 2005 my constituent Steven Gallant did a bad thing for which he is serving a life sentence in prison.

“But on November 29 he was the third man on London Bridge, he wrestled the knife-wielding murderous terrorist to the ground so that police marksmen could shoot him dead.

“Steven is rightly serving life in prison but will the prime minister congratulated and pay tribute to Stephen for his bravery that day which no doubt saved lives?”

Johnson said Turner had made a “very good point” which he thought all MPs would agree with.

The PM went on: “I am lost in admiration for the bravery of Stephen Gallant and indeed others who went to the assistance of members of the public on that day and fought a very determined terrorist.

“It obviously is not for the government to decide these things but it is my hope that that gallantry would in due course be recognised in the proper way.”