Mr Garrett quashed late last month restaurateur Neil Slater's plan to build a restaurant with overnight accommodation at Nobbys, despite support from local and state governments and many Hunter residents.

Mr Garrett said at the time he was concerned the proposed development would "significantly damage the heritage values of this Newcastle icon".

The former post office building is another of city's heritage icons and has succumbed to squatters, vandalism and neglect.

The previous federal government sold the building for less than $2 million in 2002.

The owner, Sydney-based developer Sean Ngu, has plans to develop it into a nightspot but has not begun work since the Land and Environment Court cleared the way in January last year.

Hunter residents, through recent Herald reports, letters to the editor and an online poll, have called for government action to protect the former post office from further deterioration.

Suggested options include buying back the building or forcing the developer to secure the site from further damage or act on development plans.

A spokesman for Mr Garrett said the former post office building was not something the minister could comment on.

Mr Garrett understood the management of the building was the responsibility of the private owner and subject to the requirements of Newcastle City Council and the NSW Department of Planning.