The federal budget papers say the government's civilian workforce will grow modestly next year, with most extra jobs in national security and intelligence, though the Defence Department is an unexpected loser.

The government's non-military staffing will increase to 167,484 full-time-equivalent jobs, about 900 higher than in 2017-18, but the Coalition said that was still comparable to the workforce in the later years of the Howard government.

The government boasted it had kept numbers low while Australia's population increased and the private sector expanded.

The Department of Human Services is set for a large share of cuts, with another massive drop in staff forecast in a move that will anger unions and community services advocates.

Nearly 1300 positions will go at the department in 2018-19, following on from the 1200 cut in last year's budget.

However, the department will pay contractors to run call centres, and will use more than $50 million set aside from its budget to improve call-waiting times.

No end is in sight for the department's efforts to chase welfare debts, including its maligned "robo-debt" program, which is predicted to be extended.

The Department of Foreign Affairs and the Tax Office were other winners from the Coalition's fifth budget since returning to power, gaining 40 more full-time staff each, while the Defence Department will lose more than 1000 positions from a mixture of cuts and other changes, despite benefiting from a large staffing increase last year.

The government is pouring money into agencies moved into the new home affairs super portfolio. The Australian Federal Police, the Australian Criminal Intelligence Commission and AUSTRAC will gain staff and funding in 2018-19.

Another agency moving into home affairs, ASIO, will add 120 full-time jobs as the government directs its focus on security after a major machinery-of-government shake-up last year. The spy agency will be boosted by an extra $24.4 million in 2018-19.

The National Archives and the National Library of Australia will face job cuts, with 10 staff set to be lost at the archives and 12 at the library.

The troubles surrounding the pesticides authority's controversial move to Armidale continue. It will receive $10 million for IT reforms to help it move, as well as about $25 million to assist the relocation from Canberra.

While the Coalition still backs the Australian Pesticides and Veterinary Medicines Authority's move north, a wholesale relocation of agencies into the regions was absent from the budget.

However decentralisation will continue with jobs from six agencies to move into the bush. Positions from the Office of the Registrar of Indigenous Corporations will move from Canberra to Darwin, some Prime Minister and Cabinet jobs will relocate from Melbourne to Shepparton, and the Unique Student Identifier Register will move from Canberra to Adelaide.

Twelve jobs from the Infrastructure department will also relocate to the regions.

The Coalition revealed that its major inquiry into the APS, announced late last week, would cost $10 million, which would come from Malcolm Turnbull's department's budget. It also flagged a separate $7 million review of the new home affairs portfolio to find "efficiencies" and reduce duplication.

The budget provides large sums for upgrades to the public service's digital infrastructure, which is expected to be a focus of the APS review. The Department of Home Affairs will receive $130 million for IT upgrades and $316 million will be spent on Human Service's ageing technology.

The government expects its total wages and salaries bill to increase by 1.96 per cent, or $393 million, in 2018-19, and by almost $1 billion, at 4.68 per cent, across the forward estimates.

Community and Public Sector Union national secretary Nadine Flood said the Coalition had delivered a "smoke and mirrors" budget that sold off public services to big business and undermined agencies.

"The government has continued to wreak havoc on the public sector in this budget, on top of the 18,000 jobs already cut under the Coalition," she said.

"The budget maintains destructive policies including the so-called 'efficiency dividend', the arbitrary cap on Commonwealth staffing numbers and the ballooning use of contractors, consultants and labour hire."