A union chief has called for talks after Asda bosses lost an equal pay fight with store workers which could have implications for supermarkets and other retailers.
Susan Harris, the GMB union’s legal director, urged Asda bosses to “sit down” and reach agreement on back pay.
She said the Supreme Court ruling was “amazing” news for Asda store staff.
More than 40,000 Asda store workers, about two-thirds of whom are women, brought equal pay claims after complaining that staff working in distribution depots unfairly get more money.
Asda bosses said store jobs were not comparable to distribution centre jobs.
The store workers, who are represented by law firm Leigh Day, made sex discrimination claims, saying they historically got less because most store workers are women while most distribution depot staff are men.
Lawyers representing the store workers say distribution depot workers get between £1.50 and £3.00 an hour more.
Supreme Court justices were asked to consider whether Asda store workers are entitled to compare themselves to distribution staff for equal pay purposes.
They ruled against Asda bosses on Friday after considering arguments at a hearing in July.
Store workers making claims are GMB members.
“This is amazing news and a massive victory for Asda’s predominantly women shop floor workforce,” said Ms Harris.
“Asda has wasted money on lawyers’ bills chasing a lost cause, losing appeal after appeal, while tens of thousands of retail workers remain out of pocket.
“We now call on Asda to sit down with us to reach agreement on the back pay owed to our members – which could run to hundreds of millions of pounds.”
Lawyers say the ruling will have implications for supermarkets and other retailers.
In 2016, an employment tribunal decided that store workers were entitled to compare themselves to distribution staff and that decision was upheld by Court of Appeal judges in 2019.
Asda bosses then appealed to the Supreme Court.
Lawyers say the store workers’ fight will not end, and litigation could run on for years.
They say the next stage would involve an employment tribunal deciding whether specific store and distribution jobs were of “equal value”.
If judges decided that different jobs were of “equal value”, the litigation would then enter a third stage.
Lawyers say an employment tribunal would then consider whether there were reasons – other than gender – why people working in stores should not get the same pay rates as people working in distribution centres.
Lauren Lougheed, a Leigh Day lawyer, said: “We are delighted that our clients have cleared such a big hurdle in their fight for equal pay.
“Already an employment tribunal, the employment appeal tribunal and the Court of Appeal ruled that these roles can be compared, and now the Supreme Court has come to the same conclusion.
“It’s our hope that Asda will now stop dragging its heels and pay their staff what they are worth.”
An Asda spokesman said: “This ruling relates to one stage of a complex case that is likely to take several years to reach a conclusion.
“We are defending these claims because the pay in our stores and distribution centres is the same for colleagues doing the same jobs regardless of their gender.
“Retail and distribution are very different sectors with their own distinct skill sets and pay rates. Asda has always paid colleagues the market rate in these sectors and we remain confident in our case.”
Five Supreme Court judges dismissed Asda’s appeal and unanimously ruled in favour of store workers.
One, Lady Arden, said: “This is clearly a very substantial case for Asda. At the time of the hearing before the employment tribunal in June 2016, Asda had around 630 retail stores and employed approximately 133,000 hourly-paid retail employees.”
She indicated that the litigation would now proceed to the next stage.