The government is failing in its historic duty of care towards frontline troops who put their lives on the line in Iraq and Afghanistan, forces charities and campaigners claim.

There is growing anger in the service community that the Military Covenant, which says soldiers should always be able to expect fair treatment in return for the rights they forgo, is not being upheld.

The newly-founded British Armed Forces Federation, Baff, says that the covenant is "now a dead letter". And in an unprecedented move, the Royal British Legion - widely known for its poppy appeal and welfare work for old soldiers - is to launch a campaign demanding that the government upholds the covenant and provides its armed forces and their families with proper care in return for asking them to risk making "the ultimate sacrifice for their country".

The campaign aims to "address the growing sense of disillusionment among service personnel and veterans about their treatment by the state".

"The Legion believes that our servicemen and women deserve more from their government. By committing themselves to put their lives on the line for their country, they deserve immediate medical treatment and just compensation if they are injured," the organisation says on its website.

Pressure on the government is growing after six men died under enemy fire in one of the bloodiest weeks in Iraq and Afghanistan. It includes:

· The Legion's campaign, to be launched during the autumn party conference season, will highlight medical care, military inquests and iniquities in the compensation system for injured troops;

· The rising toll of the seriously injured, with casualty figures for this year already set to outstrip the whole of 2006;

· Growing concern about the mission purpose in Basra, where soldiers told MPs troops face "nightly suicide missions";

· Soldiers losing faith in their equipment - particularly the Snatch Land Rover, which is extremely vulnerable to roadside bombs

Last year General Sir Richard Dannatt, the head of the army, warned that the government was in danger of breaking the covenant.

Published as an army doctrine the covenant states that: "Soldiers will be called upon to make personal sacrifices - including the ultimate sacrifice - in the service of the nation. In putting the needs of the nation and the army before their own, they forgo some of the rights enjoyed by those outside the armed forces. In return, British soldiers must always be able to expect fair treatment, to be valued and respected as individuals, and that they (and their families) will be sustained and rewarded by commensurate terms and conditions of service."

Douglas Young, chairman of Baff, told the Guardian: "If the military covenant is anything other than spin and hot air, then it has to be at the forefront of policymakers' minds whenever defence policy is being formulated and not just trotted out when there's a good news story. The sacrifices made by members of all three armed services in Iraq, Afghanistan and elsewhere in the past few years have been immense and in return they need to be recognised with the special consideration that the covenant appears to promise."

A spokesman for the Legion said it had decided to focus on medical care, coroners' inquests and compensation. Last month it emerged that a civilian typist with the RAF received a payment of £484,000 after injuring her thumb at work while a 23-year-old paratrooper, Ben Parkinson, who will need care for the rest of his life after a serious landmine injury, will be given £152,150. Many injured personnel have still to receive their payments.

Mounting fatalities have added to the backlog of inquests, with more than 100 families waiting to hear the coroner rule how their relative died. The Legion is looking at whether the government should be providing legal counsel.

The Legion spokesman said: "This is not an Iraq/Afghanistan campaign. It is for the whole of the service community. However, it's true that the service charities have seen an increase in their workload as a result of certain operations."

Ernie Stables, of the British Limbless Ex-Service Men's Association, said: "We have got about 43 people who have fought in Iraq and Afghanistan, who have either lost their limbs or the use of limbs, or an eye. Probably about 26 of those have come to us in the last year."

Sue Norton, wife of Captain Peter Norton, who lost his left arm and leg and suffered nerve damage to his right leg while defusing a landmine in Iraq, said she supported the Legion's campaign. Although the government helped the wounded initially, there was a "lack of cohesive support for the family as a whole".

"There's injured personnel, but there's their family too and there has been a lack of joined up thinking with regard to that," she said. "The government should be getting their finger out and doing something about it."