An architect with connections to Oasis Leisure Centre dating back to the 1970s has backed a campaign to preserve it.
Robert Guy, who first visited as a student for a university project in 1978, got in touch with the Save Oasis Swindon campaign via social media.
He described the iconic Swindon leisure centre as the last of its kind in the country.
The campaigners announced: "Robert Guy, of Arturus Architects, has thrown his full support behind the ongoing listing application with Historic England.
"He has personally written to them, urging for the Oasis to receive listed status.
"As an undergraduate Mr Guy visited the Oasis on a project. That visit that inspired him to work in leisure architecture.
"Indeed, he went on to design Bracknell’s Coral Reef complex."
Mr Guy said in his letter: "It’s my belief that there must be a way to retain this unique feature. We have more lightweight materials available than when it was built. And, if it is structurally sound, it can be clad to give a much better thermal performance than it had.
"The type of material used for the Eden project would be a most suitable material as it’s lightweight and easy to use. I would think that polycarbonate would also be suitable and can’t see why it didn’t give an uplift in the thermal performance when used six years ago.
"I suspect that the budget set aside to replace the original panels was too little. I’m sure there will be other materials which would need some research. From recollection the original panels were custom formed to each row.
"At a time where keeping and reusing is being promoted as the best way of preserving the embodied carbon within a building, it would make sense to keep this building. I understand that the building is at risk of demolition without the listing.
"The pool itself is also worthy of including in the listing. There are fewer examples of wave pools in operation and again they may disappear entirely."
The letter continued: "Because most local authorities have to use outside companies to run the facilities of this type and they are principally set up to operate as fitness centres, the operation of leisure pools is regarded as being too expensive and outside their core business.
"This has led to the closure of many of buildings of this type and a loss of facilities much appreciated by the general public. The few that remain have become centres which serve a wide catchment. The Oasis is such a building.
"The Oasis is the last remaining example of a leisure pool from the 70s - all others have suffered demolishment or substantial changes.
"It also happens to be the best example that embodies the aims of the originators and is unique in its form. If this building is not retained, then the whole building type will have disappeared."
A campaign spokesperson said: "Save Oasis Swindon have worked hard to keep the Oasis issue in the spotlight. The building has suffered numerous break-ins recently, and the campaign has conducted its own regular patrols of the site.
"The outcome of the listing will also determine if the Oasis is preservable in its current form, as the last surviving example of a major pioneering British Leisure Centre."
The campaigners have criticised Swindon Borough Council for its opposition to listing, which the council says would make working on the leisure centre more difficult.
The Oasis was one of the last leisure pools designed by Gillinson Barnet & Partners of Leeds. Mark Potiriadis was the project architect for the Oasis, and Robert Guy later worked for Peter Sargent and Mark Potiriadis from 1984 to 1991 at Sargent and Potiriadis, and with Mr Potiriadis until his death in 2007.