The government is failing to honour its commitments to troops who put their lives on the line for their country, the Royal British Legion has said.
UK forces in Iraq have been at full stretch
The forces charity said the Military Covenant - which guarantees soldiers fair treatment in return for forgoing other rights - is not being upheld.
In an unprecedented move, it is to launch a campaign to shame ministers into improving treatment of personnel.
It follows concern Britain's forces in Iraq and Afghanistan are overstretched.
The Royal British Legion campaign - titled Broken Covenant - will focus on the need to boost medical care, strengthen the system of coroners' inquests to ensure swift closure for bereaved families, and provide more compensation.
The initiative, which will be launched in the autumn, 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," the organisation says on its website.
"By committing themselves to put their lives on the line for their country they deserve immediate medical attention and just compensation if they are injured."
Military personnel are banned from taking strike action, joining trade unions or taking part in political activities.
They have legal rights to complain to their commanding officers and ultimately to the Defence Council.
Their rights as employees are enshrined in a doctrine published by the Ministry of Defence.
The Military Covenant promises: "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 forego 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."
In January, the then Prime Minister Tony Blair called for the Covenant to be "renewed" in the light of the intense and controversial conflicts in Afghanistan and Iraq.
"This is a new situation for our Armed Forces, there are new commitments necessary to make it work and make it fair," he said.
But an organisation set up last year to represent the interests of British troops, the British Armed Forces Federation (BAFF), following concern about equipment shortages, said the Covenant had to mean something in practice.
BAFF chairman Douglas Young told the Guardian: "If the Covenant is to be anything other than hot air, it needs 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."
Senior military figures have warned that British forces are stretched to the limit on operations in Afghanistan and Iraq and there have been complaints about inadequate equipment.
There is also a backlog in coroners' inquests for service personnel killed serving their country.