Tesco faces legal claim over unequal pay

British supermarket chain Tesco is facing legal claims it is paying women less than men for work of equal value, in a case that lawyers estimate could ultimately cost it as much as £4 billion ($7 billion) in compensation payments.

Law firm Leigh Day said Wednesday it had begun filing claims with the employee conciliation service Acas on behalf of 100 women, but the case could eventually apply to more than 200,000 Tesco workers.

"We believe an inherent bias has allowed store workers to be underpaid for many years," said Paula Lee of Leigh Day. "In terms of equal worth to the company there really should be no argument that workers in stores, compared to those working in distribution centres, contribute at least equal value to the vast profits made by Tesco."

The lawyers argue that in-store employees, who are largely women, are paid far less than those in the male-dominated distribution centres, even though their work is of equal value to the company.

Tesco said it had not yet seen the claim, but that it works hard "to make sure all our colleagues are paid fairly and equally for the jobs they do."