Scott Morrison has swung an axe through the public service, dumping five department heads and slashing departments in a pre-Christmas shake-up.

The Prime Minister’s shock decision will reduce the number of government departments from 18 to 14 – comparative to Bob Hawke’s 1987 reforms to slash departments from 28 to 18.

But Thursday’s move blindsided public service chiefs, who complained they had been given no warning of the Christmas purge.

“Australians should be able to access simple and reliable services, designed around their needs,” Mr Morrison said.

“Having fewer departments will allow us to bust bureaucratic congestion, improve decision-making and ultimately deliver better services for the Australian people. The new structure will drive greater collaboration on important policy challenges.”

The number of cabinet ministers will remain the same, which means there will be more ministers than departments. 

“I’m very pleased, very pleased, with the performance of all my ministers,” Mr Morrison said.

But the sacked head of the Department of Communications and the Arts, Mike Mrdak expressed his displeasure in a frank memo to staff.

“I was told of the government’s decision to abolish the department late yesterday afternoon,” Mr Mrdak said.

“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.”

Mr Mrdak’s memo to staff after learning of the Prime Minister’s moves. Photo: Twitter

Under the changes the Department of Education will merge with the Department of Employment and Skills.

A new Department of Infrastructure, Transport, Regional Development and Communications will also include the arts.

The Department of Agriculture and Water Resources will be merged with the Department of Environment.

A Department of Human Services will be established as a new executive agency called Services Australia but within the Department of Social Services.

The Department of Industry, Science, Energy and Resources will now include emissions reduction.

Five public service chiefs will be sacked in the shakeup: Kerri Hartland (employment), Renee Leon (human services), Mike Mrdak (communications and arts), Daryl Quinlivan (agriculture) and Heather Smith (industry, innovation and science).