The organisers of the world’s largest trial of the four-day working week have launched a drive to persuade more companies to try the idea, after receiving global coverage. The 4 Day Week Campaign said it aimed to persuade hundreds more companies to adopt the four-day week – crucially with no loss of pay for workers – after the six-month trial concluded this month. Autonomy, a thinktank supporting the campaign, said it would help companies in the transition during a national rollout programme. Of the 61 companies that entered the six-month trial, 56 have extended the four-day-week policy, including 18 that have already made it permanent. The campaign aims to shift the norms of work culture from 40-hour, five-day weeks to 32-hour weeks. The five-day week was itself an improvement from the six-day week that was common before the trade union movement emerged in the late 19th century. The trial gained global media coverage and commentary, including from Bernie Sanders, the prominent leftwing US senator who campaigned for the Democrats’ presidential nomination in 2016. Sanders tweeted: “Workers must benefit from technology, not just corporate CEOs.” Proponents of the four-day week argue that improvements in productivity across the economy should mean that employees can in many cases produce the same output in less time. Productivity growth has been key to the improvement in living standards over the course of decades. However, the UK government has so far not shown any enthusiasm for the idea. Martin Callanan, a business minister, told parliament in September that the government had not assessed the costs and benefits of a four-day week. Another Conservative peer, Howard Leigh, has said the policy would have a “devastating effect” because it would be “difficult for colleagues to work effectively if some are just not available for 20% of the time”. Yet some large companies have started to experiment with new approaches. Last week, Sainsbury’s, the UK’s second largest supermarket, said it would trial offering some employees the chance to work four days a week. Its trial does not involve a cut in total hours but rather allows workers to squeeze the same number of hours into four days. In November, the UK arm of the global campaign reached the milestone of 100 companies, with many citing advantages gained in employee wellbeing, motivation and retention. The campaign directors believe they can more than double that by the end of this year, given the level of interest. Joe Ryle, the director of the 4 Day Week Campaign, said: “The huge response we’ve seen to the pilot results just shows that the world is ready for a four-day working week. We’ve had 100 years of the 9-5, five-day working week and it’s time for change. Moving to a four-day week would give us all the time to be able to live happier and more fulfilled lives.”