The government should give workers the legal right to request a four-day working week from their employers with no loss of pay, MPs and unions have urged.
It comes as businesses across the country pilot or switch to a four-day week, amid emerging evidence it is good for productivity and staff wellbeing.
In a letter to business minister Kevin Hollinrake, the MPs and trade unionists said the five-day week was "no longer conducive to the needs of the 21st century", having been created over 100 years ago for an "unrecognisable" industrial and agricultural economy.
Signatories of the letter include John McDonnell, the former shadow chancellor, Caroline Lucas, the Green MP, and Mark Serwotka, the general secretary of the Public and Commercial Services (PCS) union.
It is also backed by the TUC's head of rights Kate Bell, and Peter Dowd, the Labour MP for Bootle, who has brought forward a private members' bill that would enshrine the right in law if passed.
Employees already have a right to request flexible working under the Flexible Working Regulations 2014 and ministers are now being urged to update those rules to cover a four-day week with no loss of pay.
Under the existing rules, bosses have to handle requests for flexible working in a "reasonable manner", generally by assessing the advantages and disadvantages of the application.
These requests can include the right to work from home, to compress existing hours into a number of days, or to do their jobs as "flexitime".
A genuine four-day week varies from compressed hours, which instead see workers doing longer days to compensate.
It comes after The Independent reported on Monday that over 100 companies had already switched to a four-day working week.
The 4 Day Week Campaign, which argues for the change in working patterns, has accredited dozens of companies.
To gain accreditation, the companies must prove that they have genuinely reduced working hours for staff rather than just condensed the same number of hours into fewer days.
The letter's signatories say that the Covid-19 pandemic "has shown us that the future of work can and should look different if we want to create a model that is better suited to the needs of families, women and carers".
"Numerous studies from across the world have shown that a four-day, 32-hour working week with no loss of pay increases productivity and is good for the economy.
"Furthermore, it can offer us an opportunity to create a more flexible way of working that accommodates for caregiving responsibilities and strong family life."
The letter was also signed by Labour MPs Kim Johnson, Tony Lloyd, Mick Whitley, Dan Carden, and Clive Lewis; former Green Party leader Baroness Bennett as well as Dr Mary-Ann Stephenson, director of the Women's Budget Group.
Dr Stephenson said: “The 9-5, five-day working week is an outdated model of work which sets families, carers and women up to fail.
“We’re long overdue an update to working hours and giving workers the right to request a four-day week is the necessary first step towards embracing the future of work.
“A four-day, 32-hour working week would result in a more equal share of paid and unpaid work between men and women such as childcare, housework and caring responsibilities.”
The letter was also backed by think tanks including Mathew Lawrence, director of Common Wealth; Will Stronge, director of research at Autonomy, and Dan Firth, director of campaigns and engagement at The New Economics Foundation.
Interim results of the 3,300-worker UK four-day week trial released in September found that 88 per cent of participants surveyed believed the scheme was working well for them. The trial began in June and covers from than 70 companies across a variety of industries.
Joe Ryle, director of the 4 Day Week Campaign, said: “Flexible working benefits both employees and employers as it increases job satisfaction, recruitment and retention.
“However, currently accepted forms of flexible working do little to improve wellbeing or productivity.
“We want to see a four-day, 32-hour working week with no loss of pay included in the legislation to encourage employers to embrace the growing popularity behind a four-day week.”
Asked about the idea, a spokesperson for the government’s business department spokesperson said: “There are no plans for the government to mandate a four-day working week.
“The Government is putting choice at the heart of our approach to flexible working and employers are free to offer four-day weeks if they choose to.”
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