Supporters of the former Station Hotel in Ayr fear it could be demolished after lying derelict for five years.
Once the pride of the Glasgow and South Western Railway, the French chateaux-style building is deteriorating, with bushes growing from its walls and roof.
Scaffolding has had to be erected on the station platforms to protect passengers from the threat of falling masonry.
The grade B-listed hotel has also been placed on the Buildings at Risk Register, which has recorded that some areas are in a “very poor” condition.
Campaigners have called for the 133-year-old hotel to be subdivided into a community centre and flats, or part of it could be re-opened as a “bijoux” hotel.
South Ayrshire Council said it hoped a survey of the building would be made to help decide on potential future uses.
The success of the hotel, built in 1885, spurred the railway company to build the Turnberry Hotel in 1906.
It was bought by Donald Trump four years ago and became Trump Turnberry.
Hugh Dougherty, of Heritage Railway magazine, said: “Turnberry was a result of the success of Ayr Station Hotel, at which seawater bathing was offered along with all-in train, golf and Burns tourism packages.
“Turnberry took this one step forward by building a complete golf resort, with the hotel served by the railway and packages offered to an elite clientele, including a through sleeper coach from London.
“Ayr Station Hotel deserves to be restored as a fine piece of Victorian architecture.
“The building is an integral part of Ayr railway station, and has the potential to be a worthy gateway to the tourist town.”
The hotel was described by writer Michael Pearson in Iron Roads to Burns Country as “florid in its four storeys of deep red sandstone”.
He said its designer, Andrew Galloway, “must have relished the opportunity to let his imagination soar free after a life designing engine sheds and less extravagant structures.”
Esther Davies, who leads the campaign group, said: “The hotel was opened to much acclaim. Like the railway company’s other hotels – the [now demolished] St Enoch in Glasgow and Turnberry – it was very grand.
“The marble and mosaic were by the firm which did Glasgow’s City Chambers.
“This is a large, important building of great architectural merit.
“Its position is crucial to the town. If nothing is done to conserve and develop it, then it could eventually need demolition, which would be expensive.
“The communal parts of the hotel could be the accessible community centre the town needs and the 75 bedrooms could be made into flats.”
The group is backed by Labour peer Lord Foulkes of Cumnock, who said: “The hotel is in such a dilapidated state it is an embarrassment to the proud people of the town and an indictment of those who could and should have kept it as a going concern.”
A South Ayrshire Council spokesman said: “The hotel is privately owned. However, the council is in discussions with representatives of the owner to undertake a survey of the building.
“The survey will hopefully inform the next steps regarding the future of the former hotel.”
A spokesman for Network Rail, which owns the station, said: “We are liaising closely with the council to support the authority as it seeks to resolve this issue.
“Our priority is to ensure the continuing deterioration of the building is addressed and that it does not affect the safe running of the railway.”
The hotel’s owner, believed to be Malaysian businessman Eng Huat Ung, could not be contacted. No one from Trump Turnberry was available for comment.