Thousands of people with severe mental illness are being turned away by their doctors when they seek help in a crisis, the charity Rethink said yesterday.

It found 28% of patients with a long-term history of serious mental health problems were shunned during a relapse in the past three years by the NHS staff who were supposed to be caring for them.

Four years ago the government said mental health would be one of the top three priorities of the NHS with a clear set of national standards, including written information for all service users about their care plan and how to access services at any time.

But the biggest survey of the experience of service users found 34% had no written information about their mental health problem, local services or treatment options.

Cliff Prior, the charity's chief executive, said: "Although progress is being made, thousands of service users have yet to see that reflected in their quality of life. People still do not have the information and choice of treatment options needed for the best chance of recovery."

The survey showed only 1% of mental health service users were happy with their quality of life.

The findings were based on a detailed postal survey of service users known to Rethink, formerly the National Schizophrenia Fellowship, and other mental health charities. It attracted more than 3,000 replies, the biggest sample achieved in this area of research.

On average they had 17 years' experience of using mental health services, mostly for severe conditions of manic depression, depression and schizophrenia. The average age was 46.

The survey found 48% of service users with a severe mental illness did not know, or could not be sure if they had a care plan. The implication was that they were unable to represent their views about the type of treatment they needed and were unable to hold the professionals to account for a poor standard of service.

Nearly one in five did not know how to access out-of-hours help and 15% said they had to rely on family or friends. Almost nine out of 10 were taking prescribed medicines and 34% said medicines with fewer side effects were their top priority.

Helen Gilburt, a service user, said she was diagnosed with a personality disorder in 1996 while a PhD student and twice took big overdoses to convince doctors to admit her to psychiatric hospitals.

She said: "I now get excellent support from my therapist. But there have been times when it has been a nightmare trying to get help. Everyone should have a legal right to the right mental health care."

Mr Prior said there was no evidence that the government's strategy was providing more people with help when they knew they needed it.