The George Medal awarded to one of the civilians who thwarted the attempted armed kidnap of Princess Anne is to go under hammer.

Former heavyweight boxer Ronnie Russell, 72, punched Ian Ball twice in the head as he tried to kidnap the princess at gunpoint in central London in March 1974.

For his bravery he was awarded the George Medal by the Queen, who told him: “The medal is from the Queen, but I want to thank you as Anne’s mother.”

Mr Russell, who now lives in Bristol, is reluctantly selling the medal as he is in poor health having suffered several strokes, and wants to be able to provide for his future.

“It was something I said I would never, ever do. I am so proud and honoured to have done such a thing and be involved in it that I would never, ever sell it,” he said.

“I have always believed from that day on that the life of a member of the royal family was more valid and important that mine.

“I still considered it was well worth my while getting shot as opposed to Princess Anne.

“What I would like is whoever does eventually buy the medal, I would hope they might invite me somewhere to tell them an after-dinner story about what happened on the night.”

The medal is going under the hammer at Dix Noonan Webb in central London next month, and is estimated to sell for between £15,000 and £20,000.

The George Medal is thought to be the first award given for bravery during the attempted kidnapping to be sold (Dix Noonan Webb/PA)

It will be sold with related items, including a letter from 10 Downing Street informing Mr Russell of the award, a telegram from Princess Anne and a letter from the Met Commissioner.

Ian Ball had blocked the princess’s car with his own as it drove along the Mall back to Buckingham Palace, and fired a series of shots through the rear window as he tried to kidnap the princess.

The princess and her then husband, Captain Mark Phillips, were unhurt during the late-night ambush.

But her personal detective, chauffeur, a police constable and a journalist were all shot by Ball, who was armed with two revolvers.

Mr Russell was then a 28-year-old 6ft 2in 17-stone former boxer who trained at the same club as the Kray twins in Bethnal Green.

The area cleaning manager was heading home to Kent when he saw the incident unfold and rushed to the newly married couple’s aid.

Would-be kidnapper Ian Ball used his white Ford Escort to stop the royal car in the Mall (PA) Credit: PA

“It was very fast moving but it is as clear to me now as it was the day it happened,” Mr Russell said.

“I punched him twice. The first time was when I got out of my vehicle and I thought it was a road rage incident.

“He shot PC Hills and I went to hit him around the back of the head, and he turned and shot at me and it went through the windscreen of a taxi.”

Mr Russell said Ball was trying to drag Princess Anne from her car while her husband was pulling her back.

“She was very, very together, telling him, ‘Just go away and don’t be such a silly man’,” he said.

“He stood there glaring at me with the gun and I hit him. I hit him as hard as I could – if he had been a tree he would have fallen over – and he was flat on the floor face down.

“PC Edmonds then dived on top of him and he was arrested.”

The bizarre plot failed and is perhaps best known for the princess’s reaction to Ball’s request for her to get out so he could claim the £3 million ransom money.

He was later sent to a psychiatric hospital by an Old Bailey judge.

Auctioneer Oliver Pepys, from Dix Noonan Webb, said: “We have sold several George Medals in the past but most have been linked to the Blitz and bomb disposal in the Second World War, so to be offering this peacetime medal, with such a cracking story, is a huge honour.

“A wide variety of gallantry medals were given to the ‘Magnificent Seven’ after the event but to my knowledge this is the first to come to auction.”