A project to save one of the key architectural legacies of Charles Rennie Mackintosh is set to receive a quarter of a million pounds from Glasgow City Council.

The restoration of the Willow Tea Rooms, in Glasgow's Sauchiehall Street, is a £9m plan to revamp and secure the building and famous tea room Mackintosh, the seminal Scottish architect and painter, designed for Miss Catherine Cranston in the early 20th century.

The building, used for many years as tea rooms, is currently shut and is about to undergo the major revamp planned by its owners, the Willow Tea Room Trust.

A council report, to be considered by its Executive Committee next Wednesday, says: "The buildings are currently in a very poor state of repair and continue to deteriorate.

"They are in desperate need of urgent work, water is coming through the main roof and the gallery roof is sagging and dry rot is spreading.

"There is no heating source in the Willow Tea Rooms building and the electrical wiring is in a poor condition."

The report recommends the £250,000 funding from the council, which will enable the building to open to the public in 2018 and play a key role in the celebration of the 150 year anniversary of Mackintosh's birth.

Councillor Archie Graham, the depute leader of Glasgow City Council and chair of Glasgow Life, said: "Glasgow’s Mackintosh assets are a source of major public value for the city and represents, in a tourism context, a significant economic opportunity as a unique selling point and key strength in Glasgow’s positioning as a cultural tourism destination.

"The Willow Tea Rooms is one of Glasgow’s great cultural assets and it is of vital importance to restore and preserve this Mackintosh masterpiece for the benefit of the citizens of Glasgow and visitors from Scotland and beyond."

The council paper recommends the committee approve a capital grant of up to £250,000.

The Willow Tea Rooms in Sauchiehall Street was designed by Charles Rennie Mackintosh for Miss Catherine Cranston and opened on 29 October 1903.

Mackintosh had control of the architectural and decorative elements ranging from the remodelling of the structure itself down to the design of the cutlery and the waitress uniforms.

The Willow Tea Rooms Trust was established in June 2014 to "restore, preserve, sustain and create lasting legacy for the Willow Tea Rooms for future generations".

Celia Sinclair, the founder and chair of the trust, said: "The Willow Tea Rooms is one of the undoubted jewels of Charles Rennie Mackintosh’s incredible cultural legacy.

"The Willow Tea Rooms Trust’s ambition is to protect and enhance this treasure, unlocking the great potential of this iconic piece of Glasgow’s heritage for generations to come.

"I’m delighted that the Council is considering backing our plans as part of a wider effort to promote Mackintosh’s genius as part of the 150th anniversary celebrations of his birth in 2018."

The tea rooms, run for many years by Anne Mulhern, has moved out of the landmark building to establish a new home at the Watt Brothers store at 119 Sauchiehall Street.

The overall cost of the revamp is £9m, with more than £2m spent already.

The Trust hope to raise £2m from private philanthropists and trusts, a nearly £4m grant from the Heritage Lottery Fund, and £1m in a Scottish Government Regeneration Grant, according to the paper.

An 'Advanced Works Package' has been tendered and costed at £650,000.

This is ready to start in the near future and will ensure the project can complete in June 2018.

Money for this is coming from the Glasgow City Heritage Trust and the Dunard Fund, among other sources.