More than 100,000 workers in the UK have switched to a full-time four-day week since the pandemic, in a further sign of the revolution in the world of work inspired by Covid, according to an analysis.

Nearly 1.4 million people said they worked full-time on four days of the week between October and December 2024, an increase of more than 100,000 compared with the same period in 2019, when 1.29 million reported this work schedule, according to figures from the Office for National Statistics (ONS).

Campaigners and some economists say a four-day week benefits workers by giving them more time to relax and putting less strain on their mental health, while helping businesses by making their staff more motivated and facilitating recruitment and retention.

A further 100,000 people said they worked a part-time four-day week between October and December 2024 compared with the same period in 2019.

As a result, the percentage of people in the UK who report working a four-day week has climbed from 9.8% in the final three months of 2019 to 10.9%, representing 2.7 million across full- and part-time work.

The figures do not make clear whether those taking advantage of shorter working weeks have compressed their hours or have taken a pay cut to do so.

The 4 Day Week Foundation, which campaigns for more businesses to take up shorter working weeks with no loss of pay for staff, has reported that more than 420 companies, employing more than 12,000 workers, have adopted a four-day week since the pandemic.

This is based on the number of companies that have signed up to the foundation’s employer accreditation scheme and those who have publicised their adoption of a shorter week.

The foundation is calling for a four-day, 32-hour working week to become normal in Britain for all employees, without requiring a reduction in salary.

Sam Hunt, the business network coordinator at the 4 Day Week Foundation, said: “The nine to five, five-day week is a century-old model that no longer fits the way we live and work today. We’re long overdue an update. A four-day week with no loss of pay is about freedom – the freedom to live happier, healthier and more fulfilling lives.”

The pandemic upended the world of work for many professionals, turning hybrid working into the “new normal” for more than a quarter of working adults in Great Britain, according to ONS figures.

However, the continued tug-of-war between employers and their employees has meant some workers have had to battle for the right to keep working from home in the face of return-to-office mandates, let alone reduce their number of working days.

One local authority is leading the charge. South Cambridgeshire district council voted last month to permanently adopt a four-day week, becoming the first UK council to do so. Its 700 staff are able to opt in to the scheme, where they are expected to carry out 100% of their work in about 80% of their contracted hours, with no reduction in pay.

After a 27-month trial, the council said it had recorded faster planning applications, housing repairs and benefits processing. In addition, it said it had improved staff motivation, reduced turnover and made an annual saving of nearly £400,000 by filling vacancies permanently rather than relying on expensive agency workers.

It is understood several other councils are trialling a four-day week.

South Cambridgeshire district council had come under pressure to drop its trial by the previous Conservative government, which issued guidance stating it did not support a four-day working week in local authorities and said it did “not believe that it delivers local taxpayers value for money”.

However, the Labour government withdrew the guidance in November. Instead, it said local authorities were “independent employers” who were “rightly responsible for the management and organisation of their own workforces”.

Several senior Labour politicians, including the deputy prime minister, Angela Rayner, have voiced support for a four-day week, although the party has not embraced the policy since coming to power.

The Scottish government launched a four-day week pilot in early 2024 and the results of the year-long trial involving two public sector bodies are expected to be published soon.

Marketing and technology companies and charities have been in the vanguard of adopting four-day weeks so far, according to research by the 4 Day Week Foundation.