Bureaucrats should also expect to find fewer permanent jobs and middle managers in their departments are to be more likely to be plying their trade outside the national capital.

The budget papers cite Australian Bureau of Statistics data showing Commonwealth public sector wages growing by just 2.4 per cent in the past two years compared to the state government sector, which grew 6.1 per cent, and local government, which grew 5.9 per cent.

Finance Minister Mathias Cormann says the government's controversial public sector workplace bargaining policy has led to "responsible and appropriate wage control".

The public service's average staffing levels, currently about 167,000 full-time-equivalent civilian employees, are expected to be steady in the coming years, according to the budget, but there are plans to increase "mobility" and get bureaucrats used to moving between departments as they are needed to implement government policy.

The budget papers also reveal the government's plans to recentralise parts of the public service's administration, moving more backroom functions into the government's "shared services" model.

APS veterans might see echoes of the old Department of Administrative Services, but with a modern twist, in the plan to have 97 per cent of eligible public servants covered by six "corporate services hubs" within four years.

The plan sees the Finance Department seize much of the responsibility from the Shared Services Centre as the central agency continues to re-assert its dominance over the internal workings of the bureaucracy.

The budget papers also promise to continue making the APS "more flexible, less top-heavy and deployed more widely outside Canberra".

"The proportion of ongoing staff decreased from 91.8 per cent in 2013 to 89.2 per cent in 2016," Senator Cormann noted in the papers.

"Senior executive staff and executive level staff as a proportion of the workforce has decreased from 27.7 per cent in 2013 to 25.8 per cent in 2016.

"The proportion of APS staff working outside Canberra increased from 61.5 per cent in 2013 to 62.5 per cent in 2016."

But in better news for Canberra-based public servants, the Liberals have imposed a new set of rules on the Nationals' "decentralisation push" with future proposals having to prove a "policy connection" between the "host region" and the agency being forced to move there.

The impact on the agency's ability to hold on to its specialist staff will also be considered, as will the local infrastructure needed to support a move to the bush.

Senator Cormann said the "rationalisation phase" of his "smaller government agenda" which saw dozens of mostly smaller agencies and government bodies merged or abolished was now "largely complete".

The budget papers also confirm a rapidly expanding role for the Digital Transformation Agency with confirmation the fledgling agency will take over the strategic direction and big decisions on the troubled myGov web portal from the embattled Department of Human Services.