UK staff are working the longest hours in Europe, with some employees putting in more than 70 hours a week, research reveals.
One in four people still work 50 hours and a nearly 20% put in up to 59 hours, compared with 15% in Germany and France.
The survey of 2,600 employees in the UK, the US, Australia, Germany and France, by office supply firm Esselte, shows that more than a third of UK workers also take work home in the evening and at weekends.
Mike Patterson, UK marketing director at Esselte, said: "Our research reveals the UK to be an extremely industrious nation. Staying late to get things done is a fact of life in the modern workplace.
"By also taking work home though, we run the risk of upsetting a healthy work-life balance.
"We're already working hard and now need to focus on working smarter, by improving levels of organisation which can help cut corners and save time."
The TUC said people who regularly work excessive hours are jeopardising both their physical and mental health.
It said the Esselte survey shows why the UK's opt-out from the EU limit of 48 hours a week should be scrapped.