More than 260 workers in Leeds’s big five supermarkets have so far joined a legal fight for equal pay which could award each of them up to £10,000 in back pay.

The staff work across 84 stores at Asda, Sainsbury’s, Tesco, Morrisons and the Co-op throughout the Leeds area.

Lawyers at Leigh Day solicitors, who are acting on behalf of the workers, say that if all the eligible staff at Sainsbury’s stores in the Leeds area alone were to join the claim for equal pay, the supermarket could have to pay up to £70 million in back-payments to staff if they are found to have been wrongly under-paid.

Hundreds more supermarket workers across Leeds are likely to be eligible to join the claim which is on behalf of hourly paid store-based staff, mainly women, who claim their work is of equal value to that of workers, mainly men, who work in the supermarkets’ distribution centres.

The difference in hourly pay for a shop floor worker and a distribution centre worker at the big five supermarkets can range from £1.50 to £3. Lawyers believe the average worker could be entitled to £10,000 in back pay up to six years.

Leigh Day is handling claims for more than 45,000 supermarket workers nationally, following its success in handling a landmark equal pay case against Birmingham City Council in 2012. Equal pay claims were heard and won in the High Court, the Court of Appeal and the Supreme Court after Leigh Day fought on behalf of the women involved.

Lawyer Chris Benson

In the ruling in October 2012, Leigh Day won the right for equal pay claims to be brought in the High Court up to six years after a worker leaves the employment where pay discrimination may have occurred. The Supreme Court judgment clarified the law on this point and effectively extended the time limit for equal pay claims from six months to six years. This had huge implications for hundreds of thousands of workers.

Chris Benson, who leads the equal pay team at Leigh Day, said: “Supermarket workers have been buoyed by the success of the claims by council workers. It has given them the confidence to make similar claims.

“These claims relate to work done in stores compared to work done in the supermarket distribution centres.

“Despite equal pay laws being in place for almost 50 years, our clients believe they are still unlawfully underpaid.

“Our clients believe that store and distribution jobs are equally important to the big five supermarkets and should be paid equally. This case is not about whether the jobs are identical or even the same; it is saying they are of equal value.”