BRITISH workers are at increasing risk of burnout as the number of people working over 48 hours rises past 15 per cent, trade unionists warn today.

According to new TUC research, there are now over 3,400,000 employees doing excessive hours — up by more than 450,000 since 2010.

The number of people overworking had been in decline for more than a decade until the year the Tories came to power.

TUC general secretary Frances O’Grady said: “Britain’s long-hours culture is hitting productivity and putting workers’ health at risk.”

She also voiced concern about the impact on workers’ health, as long hours have been linked to strokes, heart diseases and diabetes.

The TUC is now demanding a reassessment of the EU working time directive, which caps weekly work at 48 hours. Britain has in any case “opted out” of the cap.

The union federation argued that, while previous law had helped cut those working long hours from 3.9 million in 1998 to three million in just 12 years, new rules that are “too weak” have led to a relapse.

Ms O’Grady added: “We need stronger rules around excessive working.

“David Cameron will not convince people to vote Yes in the EU referendum if all he’s offering is ‘burnout Britain’.”

The biggest increases in the number of overworked employees were seen in Wales and London.

While men still seem to be disproportionately affected by the problem, more and more women are working long hours — 873,000 are currently doing more than 48 hours a week.

Education, manufacturing and construction continue to be the sectors with the highest number of overworked employees.