A 25-year-old woman was trapped in her own home - because she is deemed to be too disabled for a powered wheelchair from the NHS.

Donna McKeown, 25, was too heavy for anyone to push around in her manual wheelchair. Her electric one was taken away to cut costs, her family claim they were told. As a result, Ms McKeown was forced to stay indoors for eight months.

"She couldn't go anywhere," said her mother, Christine. "I am just not strong enough to push her, especially if there is any hill. So she just stayed at home for eight months."

Ms McKeown, however, was lucky. A resident of the Quarriers Village near Bridge of Weir, she eventually gave up on the NHS and got a new chair from the charity instead.

Officials at Quarriers are appalled. They believe Ms McKeown - and another unnamed client - have been let down because of financial constraints on the distribution of wheelchairs.

The catch is simple. The NHS is no longer issuing powered wheelchairs to people who cannot control them themselves. Ms McKeown, who has complex physical and learning disabilities, including giantism, needs someone else to control her electric chair, so she cannot get one from the state.

Kate Sanford, policy officer at Quarriers, said: "When someone's variety of opportunities is already limited by their physical and learning disabilities, the value of attendant-controlled powered wheelchairs can be immense. It may only be a different route to the shops that includes a steep slope, but it makes a huge difference to have that choice.

"How can a decision that places already significantly disadvantaged people at a further disadvantage possibly be justified?

"Regardless of budgetary constraints, the fact remains that some of the most vulnerable people in Scotland are being penalised. Whatever the cost savings of this decision have been, the price paid is too high."

Quarriers argued for months that its clients should get the wheelchairs, but was told, again and again, that funding was a problem. The Scottish Government yesterday said there were strict criteria for who should get powered wheelchairs and insisted these were based on whether they would be safe to use.

Ms Sanford and her colleagues, however, believe money is behind the problems, not safety. As electric wheelchairs improved, more people wanted them and demand outstripped supply, officials suggested.

The government, in a letter to Quarriers, said: "While modern technology can get round most physical disabilities, those with learning disabilities, challenging behaviour and those with sensory deficits are typically excluded from the provision of power chairs."

The charity has now provided two of its clients with the attendant-controlled electric chairs. Mrs McKeown, 49, from Pollok in Glasgow, is grateful for the help but fears for the future.

She said: "Donna is leaving Quarriers to go into independent living. What happens if her chair breaks down and she needs a new one?"

The chairs can cost thousands of pounds, with prices depending on how they are adapted for individuals. The people judged too disabled for a wheelchair may not have to wait until the next spending review, later this year, to find out if they can get one.