Thousands of current and former female staff have been in dispute with North Lanarkshire Council for more than eight years arguing they were earning less than men in comparable but different jobs. Some have died while waiting for the case to be settled.
In March, lawyers and unions hailed a major development when the council conceded at an ongoing employment tribunal that some job gradings — of around 2000 female home-support workers, playground supervisors and school patrol staff — were "unsuitable to be relied on". But the council has since refused to discuss settling these claims, they say.
Now industrial dispute mediator Acas has been asked to step in, while union leaders are planning a publicity campaign calling on the council to take action.
Carol Fox, of Fox and Partners solicitors, who is representing more than 1100 female home support workers, said they had requested the intervention of Acas to bring all parties round the table to "engage in serious discussions". She said: "I am gravely concerned about the position of North Lanarkshire Council and their unwillingness to enter into discussions.
"Delaying it is not going to make the problem go away and it is denying home support workers the money they are due."
Fox said around 22 clients in the equal pay claim against North Lanarkshire had died before their claims had been settled. She added: "We want the council to engage through Acas in constructive discussions before any more of our women die."
John Mooney, branch secretary for Unison North Lanarkshire, said the union would be launching a publicity campaign at the end of June involving advertising trailers, posters and leaflets with the message: "Pay up on equal pay".
He said the union had written to the council to request talks but the response had been "absolutely zero".
"At the least they should be settling on the groups they have made the concession on," he said. "But the longer they keep this running, not only is the amount of compensation getting higher, the amount of taxpayer's money they are wasting on lawyer's fees is getting higher."
A spokeswoman for Acas confirmed a formal offer of conciliation had been made to the parties. But she added: "There are no conciliation meetings planned."
In February, South Lanarkshire Council settled an equal pay dispute involving more than 3000 people, at an estimated cost of £75 million.
North Lanarkshire Council has previously settled a "first wave" of equal pay cases dating up to before January 2007, typically involving carers, cleaners and catering assistants.
A spokesman for North Lanarkshire Council said: "The council continues to defend its position in relation to some groups of equal pay claims.
"To date we have settled or made offers to settle thousands of claims totalling more than £30m and will continue to take a view which balances protecting the council and settling claims where we believe such a course of action is justified."
Anne Marie Robertson, from Coatbridge, was a council home support worker for nearly two decades, from 1993 to 2010. The 57-year-old, above, retired from her job on medical grounds suffering from arthritis which she says was triggered by the demands of the role.
"When I started out it was mostly all housework and doing their shopping and getting pensions," she said. "All of a sudden it all changed to home support and it was more of the caring side and that was quite heavy work, such as lifting people.
"I had no idea I wasn't getting paid properly — but thinking about the things we had to do, we were very underpaid.
"It is frustrating that is has been dragging on for so many years — quite a lot of the ladies have actually died and missed out.
"It makes me feel quite angry — I think at the end of the day they will need to pay out."
Another equal pay claimant is Margaret Fisher, 64, from Wishaw, who was a home support worker with the council from 2000-2011.
She said: "I am getting frustrated. You get to the point where you think we are never going to get this money.
"Everyone I worked with, we all thought we should have been getting a better rate for the job we were doing.
"When I started the job I thought it was okay, but once you get into it and are doing the harder part of it, you felt as if you should have been getting a better rate.
"Sometimes it was going in and doing a bit of housework and cooking, but mostly at the end it was personal care I was doing — such as assisting with washing and showering."
She added: "The council's attitude makes me quite angry — especially when you are hearing now that other councils have had a settlement and paid out."