The Ministry of Defence is announcing a third round of Army redundancies later.
About 5,000 job losses are expected, as part of cuts already announced by the government to reduce Army numbers from 102,000 to 82,000 by 2017.
BBC correspondent Jonathan Beale said there could be a higher proportion of compulsory redundancies than in the first two rounds of cuts. There will be a fourth tranche later this year.
The overall aim is to help plug a £38bn hole in the defence budget.
About 17,000 armed forces jobs are scheduled to go under the terms of the Strategic Defence and Security Review (SDSR), announced in 2010.
The navy and air force have to cut 5,000 jobs each, the Army 7,000 and about 25,000 civilian staff working at the MoD face redundancy.
In 2011 a further reduction of 12,000 was identified for the regular Army, as the government sought to put greater emphasis on military reserves.
In the first wave of losses in August and September 2011 more than 2,800 personnel from across the armed forces were told they had been selected for redundancy.
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The longer the process, the more brutal it becomes – with a higher proportion this time expected to be forced to leave”
The second round of redundancies resulted in losses of more than 4,000 military personnel in June last year.
In each case, almost two-thirds of those selected had volunteered to leave the armed forces.
Both the Royal Navy and Royal Air Force are not expected to be included in this latest round of redundancies, with natural wastage and a recruitment freeze in some areas making up the rest of the cutbacks they need to make.
Our correspondent said this third round would be the largest set of cuts faced by the Army so far, and would begin on Tuesday with the identification of the specialisms and ranks to go.
He added: “The majority of those who’ve been made redundant in the first two rounds have been volunteers.
“But the longer the process, the more brutal it becomes – with a higher proportion this time expected to be forced to leave.”
The MoD insists personnel deployed or about to be deployed to Afghanistan will be exempt from the process.