Diane Dernie said the increase to £570,000 would help give 24-year-old Ben - the most badly wounded soldier yet to survive - security for the rest of his life.

The former paratrooper suffered horrific injuries when the Army vehicle he was in drove over a landmine in Helmand province, Afghanistan, in 2006.

He lost both legs and suffered a blast injury to the brain, fractures to his skull, cheekbone, nose, jaw and pelvis, crushed vertebrae, serious damage to his spleen and chest as well as a broken elbow.

Under the increase announced by defence secretary Des Browne, at least 80 troops will receive the new maximum payout.

Another 80 servicemen with less serious injuries should also see their payouts raised.

The announcement comes after Diane campaigned for a year for more money for wounded soldiers.

In January the Ministry of Defence increased Ben's compensation from £152,000 to £285,000.

Diane, 50, said: "I'm elated, this is the best possible news. It's enough money, if we are careful, to cater for Ben's needs once we are gone.

"We will be living with him and we hope he will recover sufficiently to live independently.

"But the effects of the head injury were absolutely devastating and there will only be slight improvements over years."

Ben was serving with the 7th Parachute Regiment Royal Horse Artillery when he was injured.

He also lost years of memories - the last thing he can recall was serving in Iraq in 2004.

Ben spent many months at the army's rehabilitation centre at Headley Court, Surrey.

He will live in a specially adapted bungalow in Bessacarr, with his mum and stepdad Andy Dernie.

Diane said she would continue to campaign for compensation for soldiers, including a cap on the maximum payout.

She also paid tribute to the "incredible" support the family had received from other military families and the public which helped raise more than £250,000 for a legal fighting fund.

Diane added: "Ben is the worst injured so far, but there will be others who will need more.

"The campaign for compensation is because of a lack of preparedness by the Government.

"If you are going to fight two conflicts at once you should be prepared for casualties."