The Highgate Society is calling for thousands more signatures on its petition to save historic Athlone House on the edge of Hampstead Heath from demolition.

The society has got more than 1,100 signatures on its online petition calling on Camden Council to reject plans to knock down the 19th century mansion, off Hampstead Lane, and rebuild it as an eight-bedroom luxury home.

But they could need a total of 8,000 to get the petition debated at the town hall, unless campaigners can prove that the case relates to a local issue that only affects up to two wards, for which they would only need 500.

As well as signatures, hundreds of emails crying out against the proposals have been “rolling in” to the council’s planning department, according to society spokesman Liz Morris. “Clearly, the community feels very strongly about Athlone House,” she said.

The current bid to demolish the former NHS hospital is the second in four years. On appeal of the first application, the planning inspector ruled that the derelict mansion could potentially be replaced with a more attractive building.

An Athlone House spokesman said: “The planning inspector... concluded that a new house would be acceptable subject to a high standard of design.”