Public Health England will have four regional “hubs”, a series of local “units”, and employ around 5,000 staff, according to latest Department of Health documents.

Details of the new national public health body’s operating model were published today, following months of speculation on the government’s plans.

The plans state that the DH has “identified approximately 5,000 highly trained and dedicated members of staff” within existing organisations, such as the Health Protection Agency, that it wants to transfer to Public Health England in April 2013.

It expected a “significant majority” of staff transferred to PHE to continue in their current roles, but said full details of the transfer process would be published in June followed consultations with staff and unions in October.

The document added that the government expected to appoint a chief executive designate for PHE this coming April. The chief executive designate will then appoint a senior team and further develop and implement the agency’s operating model during 2012-13. It is due to assume full powers on 1 April 2013.

The plans also set out the agency’s expected organisational design. This will include a national office, four regional hubs and local units that report to the hubs. The hubs will be conterminous with the NHS Commissioning Board’s regional “sectors”.

The local units, which will support public health teams in councils, will “develop from the 25 current health protection units of the Health Protection Agency”, it said.

The document emphasised the “operational independence” of PHE as an executive agency of the DH, stating that it would have an advisory board “to provide external challenge and expertise”. The board will be chaired by the chief executive and comprise at least three non-executive directors.

Ministers had originally planned for it to be a department within the DH but changed it to an executive agency in June in response to the Future Forum’s concerns over its status and autonomy.

The DH also published today a document setting out more details on the future public health function of local authorities. Further policy documents are due in the New Year.

Faculty of Public Health president Lindsey Davies said: “We have been waiting for a very long time for these documents and it’s good to see some decisions at last.”

She said the establishment of a board with non-executive members was a “positive step towards the independence we have been seeking for Public Heath England”.

But professor Davies added: “We would be much more reassured if there were an independently appointed chair able to hold the chief executive to account.”