Premier Chris Minns has announced sweeping changes to the NSW public service, including the sacking of three department heads and the dissolution of DPC.

Secretary of Treasury Paul Grimes, Education Secretary of Georgina Harrisson and Transport  secretary  Rob Sharp will all be departing the NSW public Service, Mr Minns told a media conference early on Friday morning.

He has also foreshadowed the end of the cluster model, which has seen departments, agencies and organisations arranged into groups.

“We have a strong team of Ministers and I want them supported by excellent public service advice and high-quality Cabinet decision-making processes,” Mr Minns said.

The Department of Premier and Cabinet will be dissolved from July 1 and replaced by a new Cabinet Office and separate Premier’s Department.

Long-time NSW public servant Peter Duncan, a former Roads and Maritime CEO and deputy DPC director General, has been appointed acting DPC secretary and will lead the establishment of the two new entities.

Current DPC secretary Michael Coutts Trotter has been appointed acting secretary of Treasury, replacing Mr Grimes.

TfNSW COO Howard Collings will act as Transport secretary and senior education department bureaucrat Murat Dizdar will be acting Education secretary.

Mr Minns said further changes to the structure of the public service are being considered from July 1, including the end of the cluster model.

The Cabinet office would “restore robust Cabinet practice and decisions informed by expert policy and legal advice,” Mr Minns said.

The two new offices will be established using existing resources.