Shocking footage of the attack, which happened on 1 July last year, shows Lewis Livingstone, 19, kicking the victim and forcing him off his bike.

The victim, then 28, was just "going about his day, having just bought some food", when Livingstone, who had been stood at a bus stop, assaulted him, investigating officer Detective Constable James Hunt said.

Livingstone, from Enfield in north London, was sentenced at Hendon Magistrates' Court on 15 March after pleading guilty at an earlier hearing to attempted robbery and possession of a bladed article.

He was also subject to a suspended sentence for a previous offence for which he will now have to serve the 18-month sentence, bringing the total to eight years' imprisonment.

The victim had medical help at the scene before being taken to hospital, where his injuries were found to be not life-threatening or life-changing. But he claims he is "still not over the shock and fear" resulting from the unprovoked attack.

CCTV footage shows Livingstone unsheathing a large knife and scaring the victim away. He then mounts the bike but the Deliveroo driver runs back and lunges at him in an attempt to prevent the bike from being stolen.

According to the Metropolitan Police, as they lay on the floor, Livingstone retrieved his knife and stabbed the victim in the abdomen in front of onlookers.

As the victim screamed for help, some members of the public intervened to stop the attacker and hold him back before police arrived and arrested him minutes later.

One witness said that upon being asked why he carried out the attack, Livingstone simply responded: "Is he dead?"

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A victim impact statement said: "I believe this man was going to kill me, had the people not come to my rescue.

"I am still not over the shock and fear. I spent the night in hospital having nightmares. I still have a lot of pain on my side and hands as a result of being stabbed. I am now in the queue waiting for surgery on my hands."

Investigating officer Detective Constable James Hunt said: "The victim continues to suffer with the physical and psychological impact of this incident.

"He was going about his day, having just bought some food, when he was thrust into a terrible ordeal.

"I know he is incredibly grateful to the people who came to his aid. Were it not for their bravery, this incident could potentially have been far worse."