The NHS has been accused of "lazy fatalism" in its treatment of the seven million people in the UK with mental problems and learning difficulties because of a belief that they are incapable of looking after their own health.

An 18-month investigation by the Disability Rights Commission (DRC) found doctors and nurses neglected patients out of a conviction that they would inevitably die younger. NHS organisations also failed to ensure they got equal access to services.

The commission warned the Government could face a legal challenge under new disability equality laws, which take effect in December, unless discriminatory practices were eliminated.

Bert Massie, chairman of the DRC, said: "There has been a deeply inadequate response from health services and Government to target these groups which, in some cases, is compounded by a dangerously complacent attitude and a lazy fatalism."

The report found that despite a greater burden of illness, those with mental health problems and learning disabilities were less likely to get health checks. Those with learning disabilities who had diabetes had their weight checked less often than other diabetics. Those with stroke had fewer blood pressure checks.

The investigation was carried out in three primary care trusts in England and one health board in Wales and included an analysis of eight million health records.

The Health minister, Rosie Winterton, said the Government had "already started to act".

Dr Sam Everington, co-chairman of the BMA's equal opportunities committee, said the committee would discuss the report at its next meeting.