The behaviour of ministerial staff has come under renewed focus amid a New South Wales police investigation into allegations that the office of Energy Minister Angus Taylor provided doctored documents that misrepresented the travel expenses of Sydney Lord Mayor Clover Moore.

But in its response to the Thodey review of the Australian Public Service the Morrison government has ruled out any changes to the Members of Parliament (Staff) Act.

"The government does not agree to change arrangements for advisers," it said. "The government expects all ministerial staff to uphold the highest standards of integrity, and it uses a range of mechanisms to ensure they are held to account for those standards."

The Thodey review found that the number and influence of ministerial advisers has swelled.

It said that in the past two decades the number of ministerial staff had increased from 339 to 449, including a doubling in the number of public servants working as policy advisers to ministers.

READ MORE:

The review canvassed setting formal guidelines on the number of ministerial advisers who should have some public service experience as a way to strengthen links between the APS and ministers and their offices.

But the government knocked back the idea, saying it was unnecessary.

"The government, and successive governments before it, have maintained a high number of policy advisers with public service experience, and the government does not consider it necessary to set a formal guidance," it said.

Instead, it flagged plans to train public servants to be more responsive to the needs of ministers and their staff.

The government said bureaucrats needed to have "better training and guidance...on how to support ministers and their offices".

It said the Secretaries Board, which includes all department secretaries and the APS Commissioner, would update induction and training materials to "promote a shared understanding of the APS and its role alongside the Executive and the Parliament".

In his response to the Thodey review, Prime Minister Scott Morrison reiterated his view on the respective and discrete roles of the government and the public service.

"It is ministers who provide policy leadership and direction [and] we expect the APS to get on and deliver the government's agenda," Mr Morrison said.

Professor John Wanna, the Sir John Bunting Chair of Public Administration at the Australian National University, said it was not surprising that the government rejected the idea of rules governing the recruitment and behaviour of ministerial advisers.

Professor Wanna said the Prime Minster had assembled a team of advisers with a wide range of skills and experience, and codes of conduct and other stipulations could hamper the way the PM's office, and those of other ministers, operate.

"The government likes flexibility and adaptability in its [ministerial] offices; it doesn't want staff in boxes," he said.

The Thodey review found that ministers are increasingly drawing on broad networks of expertise that go well beyond the public service.

"Minister now access advice from think tanks, consultants, academics, lobbyists, interest groups and the media," it said. "This means that some ministers no longer regard the APS as their primary, or even preferred, source of advice."

Professor Wanna said many departments had lost policy skills and no longer had technical expertise in key areas, undermining their influence and adding to the reasons for ministers to seek advice elsewhere.

He said the Prime Minister was sending mixed signals on the issue, simultaneously asserting the government's primacy in developing and setting policy and exhorting the public service to be innovative and responsive in developing solutions and delivering on the government's agenda.