The Liberal-National coalition has announced it will find savings for its election commitments through a boosted "efficiency dividend", requiring public service chiefs to trim spending by $2.7 billion over four years.

Public sector unions say this will mean thousands of jobs will be shed and services reduced.

Senator Birmingham said it was a "modest change" to the existing effiency dividend, however he would not go so far as cabinet colleague David Littleproud in saying no jobs would be lost.

"I'm confident that the APS (Australian Public Service) can indeed deliver this in an environment certainly where there will be no need and no pursuit of compulsory redundancies or any of those sorts of measures," the minister told reporters in Canberra on Wednesday.

He said areas of efficiency included office space, working from home, technological changes, the use of contractors and the "senior executive structure".

"The idea of keeping some pressure across the APS to ensure that big agencies and departments were at the most efficient standard possible - that's a commonsense thing to do."

Labor leader Anthony Albanese said cutting the public service would end up costing the government money and impacting on the public, as had occurred under the controversial "robodebt" scheme.

"It costs money, because you take humans out of human services and it has devastating consequences," he told reporters in Canberra.

Labor spokesman Tony Burke said the public service had faced "extraordinary pressure" under the coalition government.

He said a Labor government would use the spending power of government procurement to promote secure jobs and would be a "model employer".

Australian Associated Press