Campaigners for the protection of modern buildings have defended their support for the listing of the Civic Centre in Plymouth.
The Civic Centre is fine post-modern architecture says the TCS
The Grade II listing was proposed by the Twentieth Century Society (TCS) and accepted by English Heritage.
It means that the crumbling 14-storey building, opened in 1962, is protected from planned demolition by the city council which is based there.
TCS said the building is something "Plymouth should be proud of".
The TCS said it had been alerted by local people to plans by the city council to demolish the building as part of a redevelopment of the city centre.
The city council says refurbishment of the building would cost more than £40m.
But TCS spokesman Jon Wright said that on inspection, it found some fine examples of post-war modernist architecture, including artwork and finishes on the interior.
Mr Wright said: "It is a high quality building of its type.
"It's surprising that English Heritage do not list more post-war buildings.
"It might sound strange now, but we shall see it as an important building in the future, in the same way that we covet Victorian houses now.
The council is appealing against the listing by English Heritage
"The heritage of the 20th century should not be discarded lightly."
He said that the building was integral to the Abercrombie plans for the regeneration of the city after World War II.
Mr Wright said: "It embodies the whole notion of the city coming back to life."
Last week Plymouth's three MPs - Gary Streeter, Alison Seabeck and Linda Gilroy - joined forces in a cross-party bid to ask English Heritage to reconsider its decision to list the Civic Centre.
The council opposed the listing when they heard it was being considered several months ago.
A Grade II listing recognises a site's special interest and warrants every effort to preserve it.