The taxpayer faces a bill of more than £850 million for making thousands of troops and staff redundant from the Ministry of Defence.
The money will go on pay-offs for those axed as a result of cost-saving measures.
The figures emerged after an influential group of MPs criticised the department's "grotesque" cuts process.
The Defence Select Committee said no civilian had been forced out of a job, while 40% of redundancies among armed forces personnel were compulsory.
Some 17,000 troops are due to be axed by 2015, and civilian staff headcount will fall by 25,000.
According to supplementary information disclosed to the committee, the estimated cost of the redundancies up to 2014-15 is £857 million.
Shadow defence secretary Jim Murphy told the Daily Mirror the public would be "aghast" at the bill.
"David Cameron is letting down our troops," he added.
An MoD source said the redundancy programme was expected to save £2.2 billion over four years.
Troops were getting far more generous pay-outs than civil servants, they added.
A spokeswoman said: "To tackle the size of the deficit the Government inherited in the defence budget meant the MoD had to cut the size of the armed forces to make them affordable and sustainable for the future.
"The savings from a smaller armed forces will far exceed the cost of redundancies."