THE charity set up to save the crumbling Mechanics' Institution has given Swindon Council a final ultimatum to prevent the listed building facing yet another winter unprotected from the elements.

The New Mechanics' Institution Preservation Trust has written to the council warning that unless it decides to undertake urgent repair works in the next few weeks, it will ask the Local Government Ombudsman or the Government to step in.

Martha Parry, trustee of the charity, has warned the council's cabinet to take firm action at its meeting next Wednesday, or risk a gloves-off approach from the Trust.

The charity wants the council to heed the advice of consultants, Fielden Clegg Bradley, which handed its English Heritage-commissioned report to the council in March.

The study showed that £2 million worth of work was needed to turn the building into a serviceable shell, while urgent works costing between £150,000 and £250,000 were needed immediately to prevent further decay.

The Trust points out that the council can bill the owner of the Emlyn Square building, Mountmead, for the work and if it does not pay up, English Heritage will step in to pay 80 per cent of the costs.

That means the biggest possible liability for the council in undertaking the repairs is that it might have to pay £50,000 towards them.

Ms Parry believes it is money much better spent than the £70,000 the council is preparing to fork out towards a study to refurbish Lydiard House.

She said: "The structure of the building is in a critical state. Any further delay will mean it will face another winter exposed to the elements and the costs of repair will spiral even higher.

"These urgent works will need to be undertaken no matter what the council determines to do with the building in the long term."

She said any inaction would boil down to simple incompetence.

"In such an event, we will take the matter to the Local Government Ombudsman or appeal to the Government to act in the last resort," she said. "We will no longer tolerate any delay in taking steps to preserve this community building."

The 133-year-old building has been empty for 42 years, since it closed as a library. The Trust wants to see it turned into a theatre, cinema, conference centre and youth facility.

The Trust is also hoping to enlist the help of a new BBC2 series, Restoration, which will focus on historic buildings and run a Pop Idol-style contest to save one of the country's treasures from dereliction.

Council leader Sue Bates (Lab, Gorse Hill and Pinehurst) said: "We will take on board the advice from the director of environmental services and take note of what the Trust members have had to say via Ms Parry's letter.

"Clearly something does need to be done about the building but the debate needs to be had at cabinet."

The Local Government Ombudsmen investigate complaints of injustice arising from maladministration by local authorities. A spokeswoman for the service said any complaint by the Trust would be considered once received in writing.