Birmingham City Council has become the latest local authority to face huge equal pay claims.
More than 50 female council workers are claiming an estimated £15,000 each in back pay and another 20,000 women, including care home staff and cleaners, could follow suit.
The legal action by Carvers Solicitors is worth an estimated £750,000 but several other Midlands law firms are actively targeting other council workers who may have equal pay claims, Birmingham Mail reports.
The women workers claim that their male colleagues have been paid significantly more for doing the same role over a period of several years.