Chief executives and senior managers from likes of Ford, Mace, PwC, Royal Mail, Thames Water and WH Smith have signed an open letter to Prime Minister Theresa May asking her to bring mental health care in line with physical health and to make mental health first aid mandatory in all workplaces.
May said last year she would update safety and health legislation to require employers to train mental health first aid responders and would extend the Equality Act to protect those with intermittent mental health conditions, such as depression, anxiety and bipolar disorder, from being discriminated against at work.
The letter argues "there are both economic and human reasons for protecting mental health in the workplace and combined, these reasons present a powerful case for updating the law".
The letter says: "As an employer we have a duty of care to our staff and whilst some employers are at the forefront of change, equalising their number of mental health first aiders with physical first aiders, we cannot afford to leave anyone behind. Cost cannot be a reason for objections because in the long run it is inevitable that making mental health first aid in the workplace mandatory will save money.
"Success will ensure employees across the country can access a trained staff member to receive initial support and guidance if they are dealing with a mental health issue at work. Success will ensure every employee has the right to a mentally healthy environment. Success will mean we can finally break the stigma of mental health in the workplace."
According to Mental Health First Aid (MHFA) England, one in six people of working age will experience mental ill health including depression, anxiety or issues relating to stress and this is estimated to cost the UK economy almost £35bn a year.
Fionuala Bonnar, chief operating officer of MHFA England, said: "[This] open letter shows that business leaders clearly recognise the need to support their employees' mental health in the same way they do their physical health.
"The change in legislation we are calling for will establish a baseline for protecting mental health in the workplace, ensuring no one is left behind. This is just one part of improving approaches to workplace mental health, but it represents an important step forward."
The Health and Safety Executive's 2017-18 annual occupational injury and ill health statistics, published last month, showed that the rate of stress and mental health problems among Great Britain's workforce is the highest in 17 years.
Cases of work-related stress, depression or anxiety rose by 13% to 1,800 per 100,000 workers in the 12 months to April 2018 compared with 2016-17. Some 15.4 million working days were lost to stress, depression or anxiety in 2017-18, which equates to an average of 25.8 days per case.
IOSH's head of policy and public affairs Richard Jones said:
"IOSH encourages an intelligent, preventative approach to managing psychosocial risks in workplaces, supported by appropriate responses to mental ill-health and its impacts.
"Well-designed occupational safety and health management systems will take account of work-related mental health issues, focusing on prevention. Organisations need to support those with mental health conditions at work and tackle discrimination and stigma. Where there is mental ill-health at work, it's important that it's competently managed and also that there are personalised return-to-work plans for workers following absence. We understand that the Health and Safety Executive will shortly be updating its first-aid guidance in respect to mental health to provide more clarity for employers.
"This Friday, IOSH will host a meeting of representatives from business, professional bodies and trades unions to discuss how to improve evaluation of the effectiveness of workplace mental health policies and practices. This will include new findings from our feasibility research into Mental Health First Aid in the workplace by researchers from The University of Nottingham."