Asda bosses have lost a Supreme Court equal pay fight with store workers.
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.
Judges ruled against Asda bosses on Friday after considering arguments at a hearing in July.
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.