Sergeant Gordon Robertson has proudly displayed his Conspicuous Gallantry Cross medal in his home since he was handed it following the Battle of Majar al Kabir.

The notorious fire-fight saw six British Royal Military policemen massacred in Maysan Governorate, southern Iraq, when the station they were holed up in was overwhelmed by an angry mob in 2003.

Just 200 metres away, paratrooper Gordon Robertson was leading his troop of 12 men when they crossed the same crowd of 200 Iraqis armed with AK47 rifles, machine guns and rocket propelled grenades - but all of the armed forces team managed to return to camp in one piece.

Now 13 years later, the war hero plans to sell off his medal - which is one down from a Victoria Cross - to help buy his son his first home.

Housing prices in the UK have soared in recent years, sparking fears young people may never own their own home.

According to the Land Registry, the average home in England and Wales now costs £157,000 but properties in desirable areas such as London sees much higher averages.

Paul Murray, of auctioneers Warwick and Warwick of Chester, explained the paratrooper had first thought of selling the medal a year ago.

But now, after finding out that the award could fetch between £80,000 to £100,000, he has decided to enter it into an auction.

Mr Murray said: "Robbo was the first serving paratrooper to be awarded to Conspicuous Gallantry Cross.

"He wasn't taken with the idea of all the glamour the powers that be tried to thrust upon him when he won this award.

"He didn't want to be put on a pedestal, forever getting put on show with his medal. He was very modest about it and underplayed the whole thing.

"So he left the army which is why he wore civilian clothing when he was presented with his medal by the Queen at Buckingham Palace."

Mr Murray said the former sergeant approached the auctioneers 12 months ago.

He asked the team how much it was worth.

Mr Murray said: "When we told him, his response was that the figure was half a house for his son.

"That is why he has decided to sell the medals now, to help get his son on the property ladder."

Sgt Robertson first joined the Parachute Regiment in 1989 and served on a number of tours in Northern Ireland during the 'troubles' in the 1990s, as well as serving in France, USA and Brunei.

The super-fit soldier broke a world record in 1989 with a colleague after they completed the London Marathon in uniform in four hours and 14 minutes - despite carrying a 40lb army rucksack - beating the previous record by five minutes.

He then went on to serve in Iraq and in April 2003, he led one of two units in the battle.

But they were soon confronted by an armed and hostile crowd, which began by throwing rocks before the first rounds were fired.

For the next two hours, the paras battled against the mob - at one point taking refuge in an empty building, only for the enemy fighters to batter their way through the walls.

When back-up finally arrived in the form of the Household Cavalry Regiment, the men were able to withdraw having inflicted heavy casualties despite running low on ammunition.

It was then the 12-man troop learned of the deaths of the six police officers who were killed just metres away, as a communications breakdown mean they were unaware of the officers' desperate situation.

Sgt Robertson left the army the following year, but carried on working in Iraq in a security role.

Before he quit, he told The Telegraph: "Everyone I know in the Army has thought or is thinking about leaving and working in Iraq.

"Most probably won't leave but some will. I've got friends out there who email me every week telling me to join them.

"They are making a fortune and it's extremely tempting for any soldier because of the amount of money they can earn in such a short time - and who can blame them."

The CGC was presented by HM The Queen at Buckingham Palace in October 2004, but as he had already been discharged, he attended in civilian dress.

The citation reads: "Robertson displayed bravery and leadership of the highest order.

"He consistently placed himself in extreme danger with no concern for his personal safety. His cool-headedness and tactical skill were inspirational.

"Despite overwhelming odds, during a sustained firefight lasting over two hours, he managed to extract his entire multiple to safety without serious injury or loss of life. "

As well as his CGC, his General Service Medal with Northern Ireland clasp is also being sold at auction, along with a letter of congratulations from the Prince of Wales, his Para beret and cap badge.

The sale will be held on April 20.

www.express.co.uk