A report by the Twentieth Century Society said many of the buildings provided a unique record of Britain's social and economic history, and it called on local authorities and developers to work together to preserve them before it is too late.
The list includes Dudley Zoo in the West Midlands, which although listed has suffered from a lack of long-term maintenance and insensitive alterations.
Another building on the list is the famous London department store Simpson's of Piccadilly, which is made of welded steel clad in Portland stone. The store has announced its closure, and the society is concerned that even if a new use can be found much of its original character will be lost.
A spokeswoman for the society said: "We are not arguing that all these buildings are beautiful, although many are, but what is indisputable is that they provide the most vivid evidence we have of the way people lived, worked and played throughout the century.
"Some are so run-down and so little cared for that without rapid action they may become unsafe, or certainly uneconomic to repair."
Bronwen Edwards, who helped to compile the report, said: "We have produced this list because many 20th-century buildings have not been listed and the criteria to get them listed is much stricter than for an older building. Even when they are listed it tends to be a controversial decision.
"The biggest danger is that they are left empty and become derelict. It then becomes very hard to restore the interior and in some cases it can be lost for ever.
"We hope this report will encourage people to look at these buildings in a new light, and perhaps find them sympathetic and energetic new owners who are keen to take them on."
Neglect Is Destroying Britain's Art Deco and Modernist Heritage
Lawn Road Flats, in Camden, London, were built in 1932 by the Modernist architect Well Coates. They represented avant-garde ideas about modern living, as well as design. Early residents included the designer Marcel Breuer, the sculptor Henry Moore, and the novelist Agatha Christie. Today the flats are owned by Camden Council and are suffering long-term neglect. The council is debating whether to use them as a hostel or to sell them.
The Daily Express building in Fleet Street, described by the satirical magazine Private Eye as "the black Lubyanka", was built in 1932. When the newspaper industry deserted Fleet Street, the building, with its distinctive rounded corners and black Vitrolite curtain walling, fell into decline. It is to be redeveloped for retail use and accommodation. The society fears that the Art Deco interior will be destroyed.
Pimlico School, London, was built in 1967 but is not listed. The Architectural Journal described it as a piece of "architectural sculpture" which expressed the expansive, socially minded spirit of the Sixties. It was designed and supervised by a single architect, John Bancroft, and it won a Riba bronze medal. The Twentieth Century Society has argued vociferously for it to be listed, but it is under threat of demolition.
Liberty's Bar, Sale, Greater Manchester (formerly the Pyramid Cinema) is one of the few cinemas outside London to be listed, but is in a poor state of repair. Built in 1933, it was designed in a neo-Egyptian style, with interior plasterwork to match. The building suffers from dry rot which needs to be dealt with if its future is to be assured. The building is currently being used as a bar/nightclub.
The Midland Hotel, Morecambe, was designed for the London, Midland and Scottish Railway and opened in 1933. One of the best-known early Modernist buildings in England, it represented the aspirations of the Thirties to provide good design for all levels of society in the once-fashionable Lancashire seaside resort. An application last year to turn the building into a casino was turned down, and it has fallen into disrepair.
Derby Bus Station was built in 1932 on the site of an old lead works in the town centre. It was designed in a typical Thirties style, with a flat roof and steel windows. It quickly acquired international fame - according to local myth, the city planners of Buenos Aires decided to build a copy. Few bus stations from this period survive. The Twentieth Century Society feels that its future is insecure after it was turned down for listing.Reuse content