Shop workers at Next have won the first stage in a fight for equal pay that could lead to a payout of up to £100m. More than 400 mainly female workers in the fashion and homewares retailer’s stores say they are paid between £2 and £6 an hour less than the company’s mainly male warehouse workers, whom they view as doing work of equal value. They also claim the warehouse staff have access to more lucrative bonuses. Next has conceded that the two types of role can be compared, the first stage in a three-step process for equal pay claims. The retailer will now have to show that the roles are not of equal value, or if they are, that there is a reason, other than gender, as to why the roles are not paid equally. The retailer employs about 25,000 store staff across 500 stores in the UK and Ireland. If all eligible staff were to join the claim, the potential cost of back pay to Next could be £100m. Elizabeth George, a barrister in the employment team at law firm Leigh Day, which is leading the Next case, said: “This is very welcome news for all the hardworking Next store staff involved in this claim. “They can now move forward, and the employment tribunal can focus on the question that is the crux of these claims: is store work of equal value to the work in the warehouses? “I believe the answer should, and will be, an emphatic yes, but only time will tell.” Lawyers acting for the Next shop assistants say that on a typical day they undertake a number of demanding tasks requiring both mental and physical agility that are comparable to tasks carried out by warehouse workers. Under employment law, those doing work of equal value, not necessarily the same work, are entitled to equal pay. The equal value part of the claim is already under way, but it could be years before a final decision. The legal action against Next first kicked off in 2018 when a claim was filed with the conciliation service Acas. The successful progress of Next’s case may open the door for further equal pay action against fashion retailers. The vast majority of cases so far have concentrated on supermarkets. In March the UK’s supreme court backed a similar claim to Next’s by thousands of shop workers at supermarket chain Asda. The Asda ruling is likely to have repercussions for thousands of workers at other supermarkets, including Co-op, Morrisons, Sainsbury’s and Tesco, who are also engaged in equal pay disputes with their employers. About 55,000 workers are involved in group claims led by Leigh Day. Last month, thousands of Tesco shopfloor workers won a legal argument in their fight for equal pay when the Court of Justice of the European Union ruled that workers can compare their role with somebody working in a different establishment if a “single source” has the power to correct the difference in pay. Unequal pay has also become a big battleground in the public sector, with female cleaners and school meal serving staff taking legal action over claims they are paid less than bin men or male street cleaners. In 2014, Birmingham city council agreed to pay more than £1bn to settle the claims of tens of thousands of women, which stretched back over many years. There have also been successful claims against Glasgow city council and Dudley council. Cumbria county council reached a settlement with 1,800 workers, paying them an average £12,079 each, in 2009. Next declined to comment.