A group of mental health charities has sent a joint letter to health secretary Alan Johnson calling on the government to recognise mental health in any potential NHS constitution.
It is signed by the chief executives of four major charities and the president of the Royal College of Psychiatrists.
The letter says: "We think it is fair to say that for most of its first 60 years, mental health has been a Cinderella concern in the NHS. Compared to the enormous human distress and costs it creates, mental health has struggled to attract financial investment and too often the standards of care offered in mental health services have been unacceptable."
It adds that "the NHS Constitution provides a unique opportunity for the government to make the commitment that the NHS will treat mental health problems on a level of equality with physical health issues and to ensure that stigma and discrimination towards people with mental health problems have no part of a 21st century health service".