Health services have a "mountain to climb" to improve the care provided to those with mental health issues, according to Deputy Prime Minister Nick Clegg.
Standards of care provided to some mental health sufferers were described as "frankly unacceptable" by Mr Clegg, who highlighted long waiting times and the treatment of children children in adult mental health wards, as causes for concern.
He added that the continued use of damaging restraint techniques and inadequate integration in the treatment of physical health of those with mental health problems also needed to be addressed.
Mr Clegg's comments come as the government launches its new Mental Health Action Plan, which sets out 25 areas where care will be improved in the health service.
Speaking at a conference with leading mental health figures in central London, the Deputy Prime Minister said that it was vital mental health be given the focus that it deserves.
He said: "Some people with mental health problems are still being treated in ways that are frankly unacceptable.
"Waiting times for common mental health services are still too long, especially in some areas of the country.
"There have been stories of people of all ages being transferred, sometimes hundreds of miles, to access a bed.
"And some children with severe mental health problems are still being cared for on adult wards.
"We recognise that we have got a mountain to climb... It's going to take a huge effort to turn that around and give mental health the focus it deserves."
Compiled by the Department of Health, the government's action plan lists a series of objectives designed to increase access to mental health and promote the integration of physical and mental health care.
As well as giving patients greater choice over where they can receive treatment, the plan also calls for "clear" waiting time limits for patients, and improved support for new mothers to minimise the risk of post-natal depression.
It also calls for improvements on the transition that young people face when leaving children's facilities and entering adult ones.
Mr Clegg added that as well as improving standards of care and services, changing perceptions of mental health, and those affected by it, were also crucial.
"All too often attitudes to mental health are outdated; stuck in the dark ages; full of stigma and stereotypes." he said: "It's time for us to bring mental health out of the shadows and to give people with mental health conditions the support they need and deserve."
Mr Clegg's comments come as a new mental illness awareness campaign was launched. Time to Talk encourages people to talk openly about mental illness and get support.
The campaign is led by the Time to Change programme, run by charities Mind and Rethink Mental Illness, with the aim of ending the stigma and discrimination faced by people with mental health problems.