Staff in the department have been told that budget cuts inflicted by the government have made the job cuts ''an urgent task'' and they have been warned of even more pain to come.

Canberra is expected to bear the brunt of the decision to slash nearly 8 per cent of DoHA's workforce, after workers were told the department could not afford to keep its present number of employees.

Departmental secretary Jane Halton told the department's 5200 employees by email that Health needed fewer bosses and more rank-and-file workers, writing that the new staffing profile would be on ''lower classifications''.

Health has more than 2000 executives at levels 1 and 2 and more than 150 senior executives, according to its most recent annual report, and more than 3500 of the department's workforce are based in the national capital.

Ms Halton said that the government's recent decision, to raise its efficiency dividend from 1.25 per cent to 2.25 per cent, meant the department had to start shedding staff.

''Recent government announcements of a further reduction to Executive Level and Senior Executive Service staff across the APS and subsequent increase to the efficiency dividend makes this a more urgent task and will require us all to work together,'' Ms Halton told staff.

''This year's business planning process has highlighted that, with no extra reductions, our 2013-14 budget allocation does not support our current staffing numbers or profile.

''To meet our budget we need to decrease our staffing numbers across the department by around 400 (full-time equivalent) positions over the coming year. We also need to position ourselves for further efficiency dividend reductions starting in the 2014-15 financial year.''

Despite making ''progress'' in improving the department's top-heavy structure, Ms Halton wrote that DoHA still had work to do about its ratio of bosses to workers.

''Over the past couple of years we have had a focus on improving our ratio of EL (executive level) staff to APS (Australian Public Service) staff,'' she wrote.

''While there has been some progress made, we have not achieved the ratio required and we need to keep working on this.''

Ms Halton said that voluntary redundancies were a possibility but there was no mention of forced redundancies.

''We must assess whether natural attrition will enable us to meet our staffing and numbers target,'' she wrote.

''I acknowledge that it may become necessary to consider further voluntary redundancies and we will keep you informed about this possibility.''

Another major department, Defence, imposed a hiring freeze last week and a decision announced in July to cull 800 workers from the executive and senior executive ranks of the public service is also expected to hit Canberra hardest.

The main public sector union the CPSU says the latest increase in the efficiency dividend will see up to 5000 public servants join the dole queue

Ms Halton's office did not respond to a request for an interview on Wednesday.