One thousand workers in the UK will get extra time off with no loss of pay in the first official pilot by the four-day week campaign under the Labour government.

The British Society for Immunology and Crate Brewery in Hackney, east London, are among the businesses to have joined the latest trial, which is being led by the 4 Day Week Campaign, as it launches on Monday.

The campaign will aim to present the findings from the latest pilot to the Labour government in the summer, as momentum builds for a shorter working week.

The trial will involve 17 businesses, who will mostly implement the four-day week, although some have opted to test a shorter working week or a nine-day fortnight, in which workers get an extra day off every two weeks. Four more businesses will join the trial later.

Nearly 200 British businesses have switched to a four-day week permanently, according to the 4 Day Week Campaign, which is run by a non-profit organisation and launched in 2022.

Winning over the government may be trickier. The Labour party has several senior politicians who have supported the four-day week, including the deputy prime minister, Angela Rayner, who last year said: “If you can deliver within a four-day working week, then why not?” But since gaining power, the party has not embraced the policy, perhaps fearful of giving political ammunition to the Conservative opposition.

When more than 500 civil servants represented by the PCS union at the Ministry of Housing, Communities and Local Government signed a petition recently calling for a four-day week, a spokesperson for the department said that a four-day week “is not government policy or something we are considering”.

However, businesses do not need government approval to go ahead, and the work pattern is being tested by new types of business. Georgia Pearson, the people manager at Crate Brewery, which serves craft beer on the bank of Hackney’s Lee Navigation, said the trial “feels somewhat groundbreaking” for the hospitality industry.

Restaurants, pubs and bars tend to be run on relatively thin margins with workers at or near the minimum wage. However, Crate is hoping that the new working pattern will improve recruitment.

“For operational teams, physically demanding service shifts can mean that off days are spent recuperating, rather than enjoying personal time off,” Pearson said. “Although we’ve never struggled with retention, we recognise the competitive advantage that comes with being ahead of the curve with a four-day week, and we hope it will aid recruitment particularly in support office roles.”

Joe Ryle, the director of the 4 Day Week Campaign, said: “We don’t have to just imagine a four-day week any more, because it’s already a reality for hundreds of businesses and tens of thousands of workers in the UK.

“We look forward to presenting the results of this latest trial to the new Labour government next summer.”