One in six workers are struggling with mental health issues, a new report suggests.

Around 15 per cent of those in work in England have symptoms of a mental health problem, according to a major review into mental health in the workplace.

Meanwhile people with mental health problems are losing their jobs at double the rate of people without such conditions, according to the Government-commissioned review.

The independent review - conducted by Paul Farmer, the chief executive of the mental health charity Mind, and Lord Stevenson, the former chairman of HBOS - estimated that around 300,000 people with a long-term mental health condition lose their jobs every year.

Analysis by Deloitte for the review suggests that mental ill health costs employers up to £42bn every year.

Half of this is accounted for by so-called presenteeism - when individuals are in work but are less productive due to poor mental health - with additional costs from sickness absence and staff turnover.

Costs associated with poor mental health for the government are up to £27bn a year, this includes costs for providing benefits, falls in tax revenue and costs to the NHS.

The annual cost to the UK economy has been estimated as up to £99bn.

The review highlights that for every £1 spent on investing in mental health in the workplace, there was an average £4.20 return.

Prime Minister Theresa May commissioned the Stevenson/ Farmer review at the start of the year.

The pair made 40 recommendations for employers, government and regulators.

The reviewers called on all employers, regardless of size or industry, to adopt six 'mental health core standards' to enhance workplace mental health.

These include making a mental health at work plan, enhancing awareness among workers, encouraging conversations on the subject and routinely monitoring employee mental health and wellbeing.

Large employers and the public sector have been challenged to go further through external reporting and designated leadership responsibility.

The government has announced that the NHS and Civil Service, two of the country's largest employers, will abide by the recommendations that apply to them in the report.