A number of senior ranking army officers face the axe when the Ministry of Defence announces the details of a second wave of redundancies later on Tuesday.
Up to 10 brigadier posts are expected to be scrapped, as well as a number of jobs at the level of lieutenant colonel.
The RAF and the Royal Navy will also start to thin out their top tier. Ministers have signed off plans that will see a number of air commodore and navy commodore posts disappearing.
In all, about 20 high-ranking jobs will go in the second tranche of a sweeping programme that has affected all three services.
The Guardian understands there will be no redundancies among RAF pilots. The Royal Marines and personnel serving in Afghanistan will also be exempted from the process, as they were last time. The Parachute Regiment is also unlikely to be affected.
A ministerial statement due to be published on Tuesday morning will set out the criteria for applying for redundancy, and the figures the military are hoping to reach.
In all, about 3,000 jobs were lost in the first round of cuts last year, and the MoD is hoping a further 4,500 will have gone by the middle of this year.
Under the Strategic Defence and Security Review, the RAF and Navy had to shed 5,000 posts each by 2015. Both services believe they can achieve this without the need for a third tranche.
The army is in a much more difficult position. The defence review, which was published in 2010, demanded 7,000 job losses, but that figure more than doubled last year as the MoD struggled to contain its ballooning budget.
The army has to shrink by 20,000 within eight years. This latest announcement is likely to reflect this pressure, with the army seeking to lose between 2,000 and 3,000 posts by the summer, and further redundancy rounds in the years ahead. The MoD argues that the Gurkha brigade has grown too big in recent years, and it is bound to face further cuts.
This will infuriate campaigners who say the soldiers, who are recruited from Nepal, are an easy target.
A "Save the Gurkha" petition has been launched by the same group which fought successfully for the Gurkhas to have the same rights as other soldiers.
Last year, 62% of those who left the armed forces were voluntary redundancies. But ministers accept the number of compulsory job losses will be higher this time - making it a much more painful process.
"We can reduce the pressure on the need for redundancies by squeezing recruitment in some areas, which will help," said a source. "The fact that the navy and the RAF will not have to go through another round of redundancies after this should provide both services with a degree of stability, which is important."
The MoD said the decisions being taken were "not easy", but ministers insist that they are necessary for the long-term security of the UK.
"We need to structure our forces to ensure that they are sufficiently flexible and adaptable to meet the demands of an uncertain future," a spokesman said.