Some Asda workers are staging demonstrations in Manchester and Brighton as an equal pay claim against the retailer begins.

More than 60,000 Asda workers have taken their case to the Employment Tribunal today over claims that mainly female store staff are being paid less than mainly male warehouse workers.

At the same time, protests are being held outside the Manchester Civil Justice Centre and outside the Trades Union Congress in Brighton, where delegates will debate the GMB union’s motion on equal pay.

The case is expected to last up to three months and mainly focuses on the fact that the predominantly female store staff at the grocer are paid up to £3.74 per hour less than warehouse workers, who are mainly men.

The union said they were “confident” that the latest stage in the equal pay claim would establish that retail and warehouse work was of equal value, and needed to be paid equally.

If the claim is successful, the GMB reported that the bill for Asda could run into billions of pounds.

The news comes after 3,500 workers at fashion giant Next won their six-year battle for equal pay for store colleagues.

Lauren Lougheed, partner at law firm Leigh Day, said the team is “very encouraged” by the result involving Next workers and hopes to be successful in the claim on behalf of Asda workers.

She added: “If we win at this Stage 3 hearing, Asda will then have to prove that there is a genuine reason for the pay difference between store workers and warehouse workers, which is not based on sex.”

GMB national officer Nadine Houghton said: “Asda workers are making history. The result of this hearing will call time on the retailers undervaluing their predominantly women shopfloor workers.

“The entire retail sector has been built on the structural undervaluing of women’s work – but GMB members are changing this.

“When the court finds shopfloor work is of equal value to warehouse work, it will be time for Asda’s majority owners – TDR Capital – to get round the table and begin settlement talks to resolve the sex discrimination in Asda’s pay structure.”

An Asda spokesperson said: “We fully respect the right of current and former colleagues to bring this case, however, we strongly reject any claim that Asda’s pay rates are influenced by gender. There are numerous different jobs within retail and within warehouses. 

“We continue to defend these claims because retail and distribution are two different industry sectors that have their own distinct skill sets and pay structures.”