When former Lance-Corporal Mark Dryden walked in to be assessed for the new incapacity benefit, the doctor asked him if he was right-handed. If it was a joke, it was lost on the soldier, whose right arm was blown off in Iraq by a roadside bomb that killed a close friend. Eight years after being promised that Britain would honour its duty to him as an amputee war veteran, Mr Dryden, 35, who has severely limited use of his other arm and post-traumatic stress disorder, was told his benefit was being withdrawn because he was considered fit for work.

“If I am fit for work, why can’t I join the Army again?” said the former non-commissioned officer in the Royal Regiment of Fusiliers. “When they said I had to go back to work, I had an anxiety attack, the depression sank back in. When it [the injury] happened I felt let down by the Army, not my unit or my mates, but the military and now I feel let down by the Government.

“It is not that I am idle. I would love to work – be a plumber or a joiner – but I physically can’t.”

Those once entitled to incapacity benefit must now be reassessed for employment and support allowance (ESA) and severely injured veterans of Iraq and Afghanistan are being told they have to undergo tests. Injured soldiers insist it makes a mockery of David Cameron’s promise to “respect and revere” veterans with special treatment.

“People in the military don’t get an easier ride than anybody else,” said Michael Ivatt, of the Soldiers, Sailors, Airmen and Families Association, who suggested that servicemen and women were pushing themselves through the pain barrier to complete tasks, only to find it meant they were “fit for work” and no longer eligible for benefits.

This month, Greg Wood, a former Royal Navy doctor, resigned from Atos, saying the system was “unfair and skewed against the claimant”. Atos, which carries out the assessments for the Department for Work and Pensions, has been criticised by campaigners but insists it operates a professional and compassionate service.

For Mr Dryden, who has no index finger, being told to pick up a £1 coin by the Atos healthcare practitioner was humiliating. He said having to go cap in hand for benefits made him feel like “scum”, adding: “It was utterly degrading. He asked if I was right handed and when I said, ‘Do you see a right hand on my body?” he said, ‘I’ll take that as a no’.”

“Once we are no use to them, they just turn their backs. They don’t want to know,” agreed former Sgt Jean Reno, 39, who has also been told his benefit is being withdrawn as he is fit for work despite severe brain injuries that have left him with no short-term memory, double vision, anxiety attacks, pain, an inability to focus for long periods and depression.

After16 years in the Royal Artillery and tours of Northern Ireland, Bosnia and Afghanistan, Sgt Reno returned from Iraq in 2005 with depression and alcohol problems. He crashed his car and suffered multiple fractures and brain damage. “I served Queen and country and was willing to make the ultimate sacrifice fighting all their conflicts. Now in my time of need they have just turned their back. If it hadn’t been for the military charities I would probably be on the street,” he said. “We just want recognition for what we have done, serving our country.”

Mr Dryden applied for incapacity benefit after being advised by a social worker that he would need it to make national insurance payments towards a pension. Along with Mr Reno, he is taking his case to tribunal but it could take months. A spokesman for the DWP said more severely disabled people were being given long-term support, adding: “We owe the men and women who have served their country a huge debt of gratitude. We will do everything to help them to find work or make sure they get benefits.”

Atos rejected criticsm of its work capability assessments, saying: “We have a large team of fully trained doctors, nurses and physiotherapists who provide a professional and compassionate service.”