Some of Britain's biggest companies have been urged to sign up for a campaign which aims to stamp out mental health discrimination in the workplace.
Every single FTSE 100 company - including Barclays, Marks and Spencer and Royal Mail - have been asked to sign up to the Time to Change pledge, which aims to develop an action plan for tackling mental health stigma.
This coincides with World Mental Health Day.
Meanwhile, Health Secretary Jeremy Hunt is to announce plans for a "data revolution" to drive up standards on mental health care in the NHS, with performance data to be published online.
Mental health problems are the largest cause of disability in the UK and cost the economy an estimated £100 billion a year, the Department of Health (DoH) said.
A recent report by the Chief Medical Officer Dame Sally Davies suggested 70 million working days were lost to mental illness last year, it added.
More than 240 employers have pledged to tackle mental health discrimination including the Bank of England, the Royal Mail, Procter and Gamble, Barclays and Marks and Spencer.
All government departments have also signed the Time to Change pledge - meaning almost half a million employees will benefit, the DoH said.
Health minister Norman Lamb said: "I am determined mental health is treated with as much importance as physical health by the NHS and society as a whole. The Time to Change pledge is an important driver in making this a reality.
"Recognising the importance of good mental health can improve colleague engagement, reduce absenteeism and enhance overall productivity and we therefore encourage other companies to join us in signing the Time to Change pledge."
In a speech at the Royal College of Psychiatrists today, Mr Hunt will announce that the first data on mental health services will be published on the website My NHS to let patients, families and staff know how their services are performing.
The Health Secretary will also ask Sir Simon Wessely, president of the Royal College of Psychiatrists, to create a dedicated group of mental health experts to identify best practice.
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The data will highlight where one trust appears to be performing significantly better than others in areas such as patient experience and care planning for a crisis, the DoH said.
It will also address suicide and self-harm prevention after it was disclosed some trusts were not following up discharged patients quickly enough, with follow-up rates ranging from 40% to 96%, it added.
Mr Hunt will also discuss plans to ensure people with mental health problems have a named clinician responsible for their care and the extension of funding for the Time to Change programme for a further year.
He will say: "I am proud this government legislated for the first time for parity of esteem between physical and mental health services.
"But however noble the ambition, parity of esteem is meaningless if it doesn't change the experience of actual people with actual mental health conditions.
"We are today confirming this Government's determination to complete that journey."
Deputy Prime Minster Nick Clegg has encouraged people to help family or friends with mental health problems and said even a text or phone call can make a "massive difference".
He said: "You don't need to be a health expert or politician to do your bit. A quick chat over a cup of tea, a supportive text or phone call or a friendly word to ask if everything's okay - today, all these things could make a massive difference.
"So, if you know someone struggling with a mental health problem, pop on the kettle or pick up your phone now - let's give them the support they need to live the life they want."