The Twentieth Century Society has reacted to growing concerns over the future of the South Bank Centre's Hayward Gallery by demanding that the Brutalist building be listed.
The society is 'increasingly concerned' that the centre's director, Michael Lynch, is considering demolishing the building to make room for other development plans on the Waterloo site.
Caseworker Cordula Zeidler said it was incredible that the centre could consider the loss of this 'incredibly strong and interesting' gallery.
She said that it was 'all the more amazing' because the building - which was designed by the Greater London Council's architecture department - has recently been successfully renovated by Haworth Tomkins Architects with artist Dan Graham.
'Once again the Twentieth Century Society would like to put forward the above buildings for Grade II listing, ' Zeidler wrote last week in a letter to the Department for Culture, Media and Sport's listing division.
'As I am sure you will be aware, the buildings have been put forward for listing twice before and gained English Heritage's support, but were finally turned down by the secretary of state, ' she wrote.
'We had believed that the threat of demolition had receded and that the growing popularity of the buildings and the popular esteem in which they are now held would safeguard their future.
'However, we were shocked that the buildings are threatened by redevelopment plans that are currently being discussed by the South Bank Centre.
'We could not believe that the South Bank Centre is ignorant to such a degree of the qualities and the immense popularity of its buildings, but unfortunately this is the case, ' she added.
Zeidler has won the backing of Michael Copeman, the chief conservation officer at local council Lambeth.
'Obviously any authority has a responsibility to make a case for a building of this quality, ' he told the AJ. 'And the Hayward Gallery is clearly a wonderful building.
'It may be that there will be an overriding case for some major changes to be made, but we would not be doing our job if we didn't question them, ' Copeman added.
However, a spokeswoman for the South Bank Centre denied that there was any reason to fear for the gallery's future. 'We have not decided anything at the moment about the future of the site and are concentrating all our energy on the work we are carrying out at the moment, ' she said.