Mr Murray, a founding partner of Sydney firm Ancher Mortlock and Murray which designed the buildings, has written to the government saying the Northbourne precinct had been nominated for heritage protection and should not be demolished before the Heritage Council had been able to complete its work. The buildings should be adapted rather than torn down.

Dickson Towers is a test case for the government as it seeks to demolish a swathe of historic public housing buildings on each side of Northbourne Avenue to make way for high-density development and generate funding for the tramline to Gungahlin.

In place of Dickson Towers will stand two eight-storey buildings, one either side of Northbourne, which the government says will act as "gateway" buildings in the same way the Dickson Towers were designed to do.

The Northbourne Precinct blocks, built for public servants between 1959 and 1962, are on the Australian Institute of Architects register of significant 20th century architecture, and on the Register of the National Estate, as well as nominated for the ACT Heritage Register.

Inspired by avant-garde 1930s architecture in Germany, Sydney Ancher designed the original masterplan for the Northbourne precinct. In all, the firm designed 169 flats including the Dickson Towers, four blocks of "bachelor flats" – bedsits that have until recently been home to single men. The demolition application covers the three on the corner of Morphett Street, each four storeys high.

Mr Murray is one of five people to object to the demolition. Another is the National Trust, whose Eric Martin said the significance of the Dickson Towers had long been recognised. The government had not properly considered designs that would protect the buildings and allow for higher density housing, he said.

The new masterplan says the significance is not only in the distinctive architecture, but in the urban design of the entire precinct, and the way the five different styles of housing give rise to "distinctive patterns" of development, all marked by open space. But it says the precinct has "lost much of its visual clarity and prominence", diminished by the newer buildings and the street trees, overgrown, coralled by the walls of private courtyards and disconnected by the multi-lane Northbourne Avenue.

"The dilapidated condition of the fences, high brick walls and closed-off private gardens contribute to the unkempt and somewhat alienating appearance of these spaces and the precinct as a whole," the masterplan notes.

While the buildings are structurally sound and maintained in fair condition, the presentation of many flats is poor and unkempt.

The area takes in nearly 500 public housing flats. The government envisages the new development will include 1134 apartments and ground-floor commercial space.

An architects' report for the new masterplan said it would have "a massing rhythm and comprehensive architectural language that reflects the layouts and cubic nature of the original precinct".

It includes "a modern reintepretation" of the bachelor flats, which the replacement buildings including a pair of four-storey buildings of similar size and scale to the existing flats. It also envisages retaining 17 De Burgh Pair Houses (with new interiors) and demolition of 30 others, the demolition of the four Owen Flats buildings and the demolition of the 16 Karuah garden flats.

In a statement on the heritage impact prepared for the government, consultant Graham Brooks said the demolition must be seen in the context of the new masterplan. He warned the entire masterplan must be implemented or the strategy would fail. New private-sector developments must be carefully managed to ensure they were in line with the masterplan.

Among other objections to the Dickson Towers demolition, a neighbour has objected to the way the new eight-storey building would overshadow his garden.

Describing the move as a "money grab", Patrick Stein said the government had not made its case to demolish such significant heritage. Heritage should only be demolished in extreme situations, and not before giving an opportunity for adaptive reuse, just because the market value was likely to be higher with empty land.

He said the proposal for the new buildings to have cubiform geometry reminiscent of the existing architecture could simply end up kitsch.