Elderly and disabled people may not survive a move from a care home where some of them have lived for 50 years, relatives fear.

The health trust which owns Osborne House, Hastings, is planning to sell the home and its 8.5-acre grounds, thought to be worth £8 million, to housing developers.

Staff and relatives are worried the 30 long-term residents, aged between 48 and 75, will not survive the upheaval.

A relative of one resident said: "They are institutionalised. Osborne House is all they know or have ever known. They have grown up together and are like a giant family. Most have no relatives outside.

"I'm convinced closing this place and splitting them up will kill some of them.

"The trust wants to cash in on the site but they should think about the effects. It would be callous and heartless to treat these people like this."

Sutton and Merton Primary Care Trust said people living at Osborne House would probably be rehoused in the community, though plans are not finalised.

A spokeswoman said the changes would take several years to implement, but staff have been told bulldozers will be moving in to start building on part of the site this September.

The relative added: "They have been told the property is not financially viable.

"They are heartbroken. About 40 people work there and some could lose their jobs. Many of the clients suffer from conditions such as blindness, cerebral palsy and severe learning difficulties and are victims of inadequate care systems when they were children.

"Nowadays most would just be cared for in the community but instead they have lived here most of their lives. The care they get is fantastic. They are very happy.

"Two residents have been here for 50 years, from when they were children. Everyone is worried about how they would cope if their home was taken away."

Osborne House, on The Ridge, is an imposing mansion set in grounds where residents grow their own vegetables and enjoy a sensory garden and nature reserve.

They take part in art, music and other therapy sessions. Some attend college courses and day activity centres.

The trust's spokeswoman said: "This group of people are now of advancing years, as is the property itself, and we are looking at ways of providing a more effective service, more in keeping with current service models.

"It would be carefully planned and the views of the people who would be most affected by a change would be integral to this.

"If accepted by the trust's board, the proposals will be the subject of a public consultation later this year."

She said if the proposals were accepted money from the sale of Osborne House would help pay for the new, community-based homes for people currently living there.