Patients receiving specialist mental health treatment could lose the care they so vitally need if the closure of a Twickenham hospital goes ahead.

St John's Hospital, in Strafford Road, was established by Elizabeth Twining in 1879 on the understanding that it was "forever thereafter to be used as and for the purpose of a hospital or dispensary".

But now it looks as if her wishes will not be carried out, as Richmond and Twickenham Primary Care Trust (PCT) look to cut costs and privatise the residential services they provide to the hospital.

Outpatient services will be transferred to new premises being developed next to Teddington Memorial Hospital.

Paul Lamplugh, whose wife Diana is a resident at the hospital with Alzheimer's disease, said: "It is not like we are talking about some out of date hospital - it was re-opened in 1995 so is modern and built specially to care for people like my wife.

"The effect this would have on Diana is that she would have to be moved somewhere else, but of more concern is that she is moved somewhere where they understand the extreme kind of illness she has.

"Patients need care which give them quality of life, rather than just putting them back into some home and drugging them up so they become a zombie.

"The idea at St John's is that they have to be on drugs to some extent, but they also give them the best quality of life that is reasonably possible.

"The PCT say they can find a provider to carry out the care for half the price at the moment and say they will find alternatives for all the patients.

"But the concern is can that be sufficient for the patient and for their proper care?"

Paul, who established the Suzy Lamplugh Trust for Personal Safety after his daughter went missing in 1986, said he also has concerns about the future of the building, run by South-West London and St George's Mental Health Trust.

"A lot of people do not appreciate the gem we have on our doorstep or that it may not be there for the future generations."

A spokesperson for Richmond and Twickenham PCT said: "The Richmond and Twickenham PCT is currently working through the tender process to commission NHS continuing care beds for elderly mentally ill patients. The new service will provide a service for all Richmond and Twickenham PCT registered population including current patients being treated at St John's Hospital."