The junior ranks of the armed forces should get an immediate £6,000 pay rise to help boost morale, the Lib Dems say, BBC reported.
It was "shameful" that many privates on their first tour of duty earned less than police constables and junior firefighters, leader Nick Clegg said.
He said the move, costing about £300m, could be part funded by cutting 10,000 "desk" jobs at the Ministry of Defence.
Ministers said pay deals for the armed forces had been among the best in the public sector in the past three years.
All military personnel were awarded a 2.8% pay rise earlier this year after the government accepted the recommendations of the Armed Forces Pay Review Body.
As a result, the basic pay of a private on operations rose to between £16,681 and £25,887.