Scott Morrison has announced a dramatic overhaul of the federal public service, cutting the number of departments and creating several new mega ones, while removing five secretaries.

The departments will be reduced from 18 to 14.

But Morrison said there were no changes to his ministry or to portfolio arrangements.

“I’m very pleased, very pleased, with the performance of all of my ministers and the work they’ve been doing,” he told a news conference.

He also said the public service shake up was not a savings measure.

This has been done as a structural issue to better align and bring together functions within the public service so they can all do their jobs more effectively and help more Australians

The new departments are

• Education, skills and employment, created from the present department of education and department of employment, skills, small and family business

• Agriculture, water and the environment, which consolidates the department of agriculture, and the environment functions from the current department of the environment and energy

• Industry, science, energy and resources, which will bring together the present department of industry, innovation and science, the energy functions of the current department of the environment and energy, and the small business functions from the current department of employment, skills, small and family Business.

• The department of infrastructure, transport, regional development and communications, consolidating the current department of infrastructure, transport, cities and regional development, and the department of communications and the arts.

Services Australia announced by Morrison after the election, will be established as a new executive agency within the social services department.

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Ten departments are unchanged, Morrison said.

The secretaries who have been dispensed with are: Kerri Hartland (employment); Renée Leon (human services); Mike Mrdak (communications); Daryl Quinlivan (agriculture) and Heather Smith (industry).

It is not known which, if any, were voluntary departures.

Morrison immediately after the election installed his own man, Phil Gaetjens as head of the prime minister’s department, and flagged more changes later.

Morrison is bringing back to the public service Andrew Metcalfe who will head the new agriculture department. Metcalfe was sacked by prime minister Tony Abbott from agriculture.

Morrison said Metcalfe would “bring considerable public policy leadership experience” to the job.

David Fredericks, presently secretary of the environment and energy department becomes secretary of the new industry department.

Morrison said the shrinking of the number of departments was “to ensure the services that Australians rely on are delivered more efficiently and effectively”.

“Australians should be able to access simple and reliable services, designed around their needs. Having fewer departments will allow us to bust bureaucratic congestion, improve decision-making and ultimately deliver better services for the Australian people,” Morrison said.

“The new structure will drive greater collaboration on important policy challenges. For example, better integrating the government’s education and skills agenda and ensuring Australians living in regional areas can access the infrastructure and services they need.”

Andrew Podger, a former public service commissioner who headed several departments, said he was “particularly pleased” to see the department of human services disappear as a department and become an executive agency (Services Australia) in the social services portfolio, although it would have been better if Morrison had gone further and made it a statutory authority.

“But at least we will no longer have the administration of social security payments in a separate portfolio from social security policy,” he said.

“The other mergers make some sense, recreating the ‘mega-dapartment’ structures from the 1987 Hawke years, particularly the combination of education, employment and training, ” Podger said.

“But the main potential benefit of fewer and larger departments is to make cabinet work better, with a smaller cabinet, and with portfolio ministers given more latitude to make decisions (and allocate resources) drawing on their junior ministers.

"If this does not happen, and more departments have two cabinet ministers, that will cause more problems, not fewer ones, particularly for the secretaries giving advice.”

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Morrison, asked who would be the senior minister in the new environment and agriculture department, defended having multiple ministers.

“The portfolio minister for the environment Sussan Ley is responsible for the environment and Bridget McKenzie, who is the minister for agriculture, will be responsible for agriculture policy, and David Littleproud is responsible for water policy, Morrison said.

It is not uncommon for departments to have multiple ministers. They have multiple ministers now. And so the officials that work in these departments respond to the minister that is responsible for those portfolio issues. So who’s the senior minister on environment? Well, it’s the minister for the environment. Who’s the senior minister on agriculture? It’s the minister for agriculture. It should be very plain.

Morrison flagged he would next week provide the government’s response to the still-unreleased Thodey review of the public service.

Mrdak said in a frank memo to staff: "I was told of the government’s decision to abolish the department late yesterday afternoon. We were not permitted any opportunity to provide advice on the machinery of government changes, nor were our views ever sought on any proposal to abolish the department or to changes to our structure and operations.”

Opposition leader Anthony Albanese said the changes were about “centralising power”.

Departments and secretaries from February 1, 2020

• Department of agriculture, water and the environment - Andrew Metcalfe

• Attorney-general’s department - Chris Moraitis

• Department of defence - Greg Moriarty

• Department of education, skills and employment - Michelle Bruniges

• Department of finance - Rosemary Huxtable

• Department of foreign affairs and trade - Frances Adamson

• Department of health - Glenys Beauchamp

• Department of home affairs - Michael Pezzullo

• Department of industry, science, energy and resources - David Fredericks

• Department of infrastructure, transport, regional development and communications - Simon Atkinson

• Department of the prime minister and cabinet - Philip Gaetjens

• Department of social services - Kathryn Campbell

• Department of the treasury - Steven Kennedy

• Department of veterans’ affairs - Liz Cosson

Michelle Grattan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.