A hero who was nearly killed after stopping a man from strangling a barmaid was given a prestigious award for his bravery by the Metropolitan Police commissioner on Tuesday.

David Nelson, 39, who spent two weeks in a coma after the attacker threw him down a set of stone steps near Richmond Bridge, was honoured by the Carnegie Hero Fund Trust.

Mr Nelson was originally given a 50 per cent chance of survival following the attack, which happened when he saw Saed Kamali Porgoo attacking the manageress in the Pitcher and Piano bar on January 13, 2004.

He bravely stepped in and helped remove him from the pub, but was then pushed down the steps. One witness said he literally flew'.

Porgoo, a paranoid schizophrenic, was arrested, stood trial and was committed under the mental health act.

Mr Nelson made a miraculous recovery and on Tuesday, alongside his wife Nikki and 16 guests, was invited to a ceremony at Scotland Yard where he was presented with the award by Sir Ian Blair.

The Carnegie Hero Trust recognises individuals who risk their own lives in helping someone else and help support them and their families for the rest of their lives.

Only two or three people are recognised each year and this was the first time it had ever been awarded by the Metropolitan Police.

Mr Nelson, who remembers nothing of the attack, said: "It was just a really special day, I feel extremely honoured. Mindblowing, just mindblowing. I still can't believe I was sitting there and given an award like that, it was very emotional.

"I felt proud but times like that make you realise what we have been through."

Nikki Nelson, 37, said: "I suddenly realised that I was going to cry and I didn't know why. David has been through so much and recognition of everything he has been through on behalf of someone else just brought everything flooding back."

Mr Nelson added: "It was lovely to be recognised, I couldn't ask for anything more than that, but I wish it hadn't happened in the first place."

The incredible support that Mrs Nelson has given him in the past two years was also recognised at the ceremony when she was presented with a bouquet of flowers by the commissioner. "It was the first time that I have ever been speechless in my life," she said.

Nora Rundell, chief executive of the Carnegie Hero Fund Trust, explained how their candidates are chosen.

She said: "No individual knows until they are in that situation what they are going to do and it is such a wonderful thing that David responded in the way her did.

"He had it in him to react spontaneously, obviously knowing because of what had happened in the run up to his own attack, he was putting himself in a dangerous situation.

"If one thing determines that someone deserves recognition, it's that the individual knew what they were doing, they knew they were risking their safety."