A four-day working week would boost productivity, a study by Oxford University economists suggested.

The gains from improved productivity could make up for the "lost" fifth day at home or enjoying leisure time,the lead researcher told the BBC, suggesting it is potentially the ultimate virtuous working circle to improve work-life balance.

It comes as it was reported Sunday that Labour is exploring proposals that would see workers enjoy a three-day weekend, but get paid the same as a five-day working week, by companies passing on efficiency savings from new technology to staff.

For the past six months, a team led by Jan-Emmanuel De Neve, associate professor of economics and strategy at Oxford University's Said Business School, has been tracking the happiness and productivity of 5,000 call centre workers across more than 20 centres.

The preliminary findings, he said, have been "really striking." By cross-referencing a huge mass of performance data with a weekly check on each of the 5,000 workers' wellbeing, scored from one to five, the results so far appear to prove the thesis.