Co-op shop-floor workers have won a key legal argument in their equal pay dispute with the retail giant.

More than 1,600 Co-op workers have taken action against the business over complaints that they are being paid less than colleagues in the firm’s distribution centres.

The mostly female shop-workers have said they should receive pay similar to the mostly male distribution colleagues, who were paid up to £3 more an hour.

The Co-op has now conceded a “comparability concession” in the case, a step towards recognising the different roles are of equal value.

However, the supermarket group said it will continue to defend itself against the claims and believes it pays workers “fairly”.

It comes after a raft of similar legal cases, including at rivals Tesco, Sainsbury’s and Morrisons, where it was also decided that store workers could be compared with distribution staff.

Tom Hewitt, a solicitor in the employment team at Leigh Day, said: “Leigh Day is delighted to be able to tell Co-op staff that they have cleared the first hurdle in their claims for equal pay.

“We hope that Co-op recognises that they can no longer deny that the work store workers do is of equal value to that of their distribution centre colleagues.”

A spokesman for the Co-op said: “Our colleagues play an important role in feeding the nation and it’s central to the Co-op’s values that we pay them fairly for the work that they do in supporting communities.

“We believe that we pay our colleagues fairly for the roles that they do, and so will continue to defend these claims.”