The number of people working excessive hours has risen by 15% since 2010, raising concerns over the potential health implications for these workers, a new study by the Trade Union Congress has revealed.
The study says the number of people working more than 48 hours per week has risen after more than a decade of decline. The figures do not include the self-employed. A total of 3.417 million people are working long hours, up by 453,000 since 2010.
The congress is now asking the government to implement stronger rules on excessive work hours, urging the government to phase out the opt-out option for the EU Working Time Directive which many employees feel they are pressured to agree to.
It said despite a growing workforce, the existing working time rules had helped to reduce long hours from 3.9 million or 17% in spring 1998 to 3.3 million or 13% in 2007 and 3.0 million or 12% in 2010.
"But the number has since increased and is back to 3.4 million (13%). There is now a strong sense that the existing rules are too weak to beat the long-hours culture, leaving too many people stuck in 'Burnout Britain."
The average working week in the UK is now 43.6 hours compared with a European average of 40.3 and limits of just 35 in France.
The congress General Secretary Frances O'Grady said: "Britain's long hours culture is hitting productivity and putting workers' health at risk. Working more than 48 hours a week massively increases the risk of strokes, heart disease and diabetes.
"We need stronger rules around excessive working, not an opt-out of the Working time Directive. [Prime Minister] David Cameron will not convince people to vote yes in the EU referendum if all he's offering is 'Burnout Britain." he said.
Those who regularly work more than 48 hours per week are at risk of developing heart disease, stress, mental illness, strokes, and diabetes, putting extra strain on the health service and the benefits service, as well as co-workers, friends and relatives.
Mary MacLeod, chief executive of the National Family and Parenting Institute told the Daily Mail: "This is yet another report that highlights the long-hours culture that is putting serious strain on family life in the UK. Every day we see headlines blaming parents for not having time for their children, meanwhile parents in the UK are having to work the longest hours in Europe to make ends meet, returning home stressed and exhausted."
The CBI however had other ideas. Deputy Director General John Cridland told the newspaper: "Managerial workers often work longer hours because they want to. Operational staff often work longer hours because they are paid for it.
"Neither group will thank the government for intervening. They don't want a nanny state," he said, adding that over regulation could severely damage competitiveness.
Men are still working more than women - 2.544 million men compared with 873,000 women in 2015 but the number of women working longer hours has increased by 18% compared with a 15% increase in men.
The biggest industries affected are mining and quarrying (64%), agriculture, fishing and forestry (43%), accommodation and food services (36%), health and social work (32%) and education (31%).
All areas in the country saw a rise in the number of long hours workers with Yorkshire and Humber seeing the highest increase of 30% in 2015 compared to 2010. This was followed by Wales (22% increase) and London with a 21% rise. Northern Ireland had a negligible rise while Scotland saw a 6% increase.