Prime minister Theresa May is to visit Norfolk today as she launches a national programme of mental health support.

Mrs May will visit construction and infrastructure firm Morgan Sindall which she has said is 'leading the way and showing that businesses can deal better with mental health issues among their employees.'

She has also praised the 'excellent work' of the Eastern Daily Press' Mental Health Watch campaign to raise awareness and tackle the stigma around mental health.

Today Mrs May will announce that more than two million public sector workers are set to receive unprecedented mental health support, and this announcement follows the publication of an independent review into mental health and employers which had been commissioned by the prime minister.

Mrs May said: 'I have made it a priority of this government to tackle the injustice of mental illness.

'Vital to this is the need to have a comprehensive cross-government plan which transforms how we deal with mental illness not only in our hospitals or crisis centres but in our classrooms, shop floors and communities.

'That's why I commissioned this important review which starkly illustrates the cost of untreated mental illness - around 300,000 people with a long term mental health problem are losing their jobs each year.

'And that has a big impact on businesses which are losing up to £43bn each year as a result.

'So we need to take action. That's why I am immediately asking NHS England and the Civil Service – which together employ more than two million people – to accept the recommendations that apply to them.

'With so many of our leading businesses leading the way in this area – and reaping the rewards as a result – I am sure that the private sector will follow suit.

'It is only by making this an everyday concern for everyone that we change the way we see mental illness so that striving to improve your mental health – whether at work or at home – is seen as just as positive as improving our physical wellbeing.'

The NHS and Civil Service will introduce a set of common sense standards to provide support for anyone with a mental health condition and help them stay in work.

NHS England and the Civil Service will:

• Introduce a set of core and enhanced standards which will ensure employees have the knowledge, tools and confidence to understand and look after their own mental health – and the mental health of their colleagues.

• Have support in place to help prevent mental illness being caused or worsened by work and equip those who have a mental illness to thrive.

• Be held to account for delivering these standards by their relevant regulators so that employees can have faith they are being introduced effectively.

The report from Lord Dennis Stevenson, a long-time campaigner for greater understanding and treatment of mental illness, and Paul Farmer, CEO of Mind and chairman of the NHS Mental Health Taskforce, includes 40 recommendations for the public and private sector.

The prime minister is also today writing to all metro mayors and key business groups including the CBI, IoD and Federation of Small Businesses to draw attention to the review and encourage them to implement the recommendations in their organisations and across their networks.