Nine historic defence sites around Sydney Harbour must raise revenue and attract more tourists, Environment Minister Tanya Plibersek has declared, even as the agency managing the sites scales back redevelopment plans in the face of community pressure.

The Sydney Harbour Federation Trust will on Thursday release a revised master plan for Middle Head in Mosman which abandons parts of the draft proposal following a backlash, but proceeds with the demolition of three 1950s timber barracks – to the alarm of heritage advocates.

Middle Head, or Gubbuh Gubbuh, has significant Indigenous, military and environmental heritage value. Credit: Sydney Harbour Federation Trust.

It no longer proposes to reconfigure Middle Head Oval or move the change facilities, retains the former military guardhouse and its currently tenanted cafe, and rules out frequent large-scale events on the headland.

Instead, the Trust is proposing to use the headland for no more than two events a year – such as heritage open days, temporary exhibitions or community festivals – and cap visitors at 500 a day. The brick buildings of the 10 Terminal will still be redeveloped, including food and beverage.