ESTATE agents are struggling to sell a museum-quality Charles Rennie Mackintosh house which comes with a £3million price tag attached.

Historians and politicians are now suggesting the seven-bedroom category A listed building - called Windyhill and located near Kilmacolm - could be bought for the nation.

Glasgow-born architect Mackintosh designed and built Windyhill - one of only a handful of architectural projects he undertook - for produce broker and merchant William Davidson in 1900.

World-renowned Glasgow publisher Walter Blackie later commissioned Hill House in Helensburgh - second only in fame when it comes to a Mackintosh design to Glasgow School of Art - when Mackintosh took him to view Windyhill. Hill House was given to the National Trust for Scotland in 1982.

The Windyhill property has changed hands several times in the last century and now Edinburgh estate agent Ballantynes has been asked to offload it by current owner David Cairns.

However, it was put up for sale eight months ago and a buyer is yet to be found.

The listing on a property website, posted in April last year, describes Windyhill as "an important and fine example of Rennie Mackintosh's work" which has been "restored by the present owner to near museum quality".

Professor of Mackintosh Studies at the University of Glasgow, Pamela Robertson, said: "It is an exceptionally important house as one of only a handful built to Mackintosh's design.

"What is essential is that it has an owner, like the current one, who is sensitive to its history and character.

"It is a property of international importance and should be preserved for future generations."

Stuart Robertson of the Charles Rennie Mackintosh Society is also keen that the house is maintained but said turning it into a museum may not be feasible.

He said: "I think it would be a good idea but the only problem is accessibility. It doesn't have the same parking that the Hill House has.

"It's obviously a wonderful property and something that should be preserved but it's good that it's still a private house because that's what it was designed for.

"The current owners have done a fantastic job and put it back together again to give it the feel of how Mackintosh designed it. They've also been very amenable to the society and myself.

"When it's sold, I'd like to see it have another owner that loves and cares for it. I'd quite happily live it in myself if I had the money to do so. It's a work of art and quite unique."

Scottish Labour's culture spokeswoman Claire Baker MSP described Windyhill as "a wonderful example of Scottish cultural history".

She added: "The fire at Glasgow School of Art is a stark reminder of the fragility of some of Scotland's greatest work, especially that of Mackintosh.

"We should be doing all within our power to ensure that future generations can be inspired by the work of our great artists and designers.

"Serious consideration should therefore be given as to whether Windyhill should join Hill House in belonging to the nation and people of Scotland."

The National Trust is unlikely to find £3m in its budget to buy Windyhill.

Communications Manager at the National Trust for Scotland, Sarah Cuthbert-Kerr, said: "The Trust has no plans to buy Windyhill, so we wouldn't offer any sort of view on the valuation and its feasibility or otherwise.

"In terms of its significance, the Trust hasn't carried out a heritage assessment, but we know that Charles Rennie Mackintosh took Walter Blackie to see Windyhill before securing the commission to design the Hill House in Helensburgh."

A spokesman for Historic Scotland, the executive agency of the Scottish Government responsible for the country's historic monuments, also poured cold water on the idea of that the building could be taken into public ownership.

He said: "The majority of Scotland's finest listed buildings remain in active use and many are also private homes. There is no reason why Windyhill should not continue in use as a family home.

"Taking a property into the care of Scottish Ministers could only be considered if an approach was received directly from the property owners themselves."

Windyhill's owner David Cairns and estate agent Ballantynes both declined to comment.