Brits work 325 more hours a year than their German counterparts - translating to roughly nine extra weeks a year, according to an analysis of 2017 data.
Slipper manufacturer Mahabis also found that the UK has the highest proportion of employees working more than 50 hours a week out of all Western European nations - with 13 per cent of Brits burning the midnight oil, compared to only 0.45 per cent of Dutch workers.
Scandinavian countries, famous for their high social security spending and strong employment rights, topped the rankings - with a large number of public holidays and a good amount of time dedicated to leisure.
While UK staff spend a disproportionate amount of time at work, Brits are inefficient compared to their European counterparts.
The UK infamously has one of the lowest productivity levels - the value of goods and services produced for each hour worked - in the G7 - with Office for National Statistics (ONS) data for 2016 showing that French workers produce more in a four-day week than Brits do in five.
Mahabis' analysis ranked 20 countries comparable to the UK on a number of factors, including hours worked, statutory leave options and the proportion of people working long days.
The slipper company analysed datasets from 2017 OECD and International Labour Organisation reports.
According to its breakdown, Brits can at least take some comfort that they are enjoying a better balance than their counterparts in South Korea and Japan, where over 20 per cent of employees work more than 50 hours a week.
Ankur Shah, the founder of Mahabis, which operates a four-day working week policy, said: “A healthy, happy workforce can drive productivity and creativity, but these figures reveal that Brits are amongst the most guilty of committing more time to their jobs rather than finding time to switch off.
“We can all do more to recognise the importance of downtime, which can benefit individuals, businesses and society as a whole.”