Twenty-six men working at a university in Wales are suing their employers for more than £700,000 over allegations of sex discrimination and unequal pay.
The men, caretakers and tradesman employed by the University of Wales Trinity Saint David, say they have been paid less than female employees in equivalent posts for seven years.
They each argue they have been underpaid by an average of £4,000 a year since 1 August 2007 and are claiming more than £30,000 each in back payments.
In total the 26 men are demanding around £736,000 from the university, as well as future wage increases to put them in line with female colleagues on the same pay grade.
On Tuesday next week an employment tribunal hearing in Cardiff will hear claims from 19 of the men. Depending on the outcome, the other seven may then have their own hearings.
All were originally employed by Swansea Metropolitan University, which merged with the University of Wales Trinity Saint David in August last year.
They are represented by Northern Irish solicitor Paul Doran, who has acted in similar pay discrimination cases for women in Birmingham and Sunderland.
Since 2011 Birmingham city council has settled thousands of cases after losing an employment tribunal ruling. Recent estimates suggest the final bill could top £1bn, leading the council to consider selling many of its prime assets including the NEC conference centre.
"The vast majority of equal pay cases involve women claiming that they have been underpaid in comparison to male colleagues," said Doran. "This case is unusual because here we have men who are alleging that they are the ones who have been discriminated against when compared to female colleagues on the same grade.
"These men have been underpaid since 2007. Had they been a female secretary or a library worker on the same grade working the same shift pattern, they would have received an additional £4,000 per year. That cannot be right and we hope that the tribunal sends out a strong message that discrimination has no place in any form in the workplace."
The men contend that their job roles have been rated as equivalent to all women employed by the university on a Grade 3 pay scale , all of whom receive a higher basic rate of pay and enhanced rate of pay.
The workmen say they were told of changes to their pay conditions in meetings with Swansea Metropolitan University senior management in 2008.
One of the men, who did not want to be named, said: "We were notified officially about the conditions in a letter after the meeting. When we received the details, we realised we were on the lower pay variety and we felt cheated.
"Some of us approached HR but it just came down on deaf ears as far as they were concerned. Most of us are afraid of the repercussions.
"How we have been treated is undoubtedly a sex discrimination issue. Our terms and conditions are far, far worse than if we were female. We have not had support from female colleagues, it has all been on the hush."
He added: "None of us wanted it to get this far, we just wanted to be treated like everyone else, out of a sense of fairness. It's a real sense of injustice for us, we feel extremely frustrated that it has had to come to this."
A spokesman from the University of Wales Trinity Saint David said in a statement: "This employment tribunal relates to events that occurred more than seven years ago at the now dissolved higher education corporation Swansea Metropolitan University and several years before its merger with the University of Wales Trinity Saint David which took place in 2013.
"It would be inappropriate to comment further while tribunal proceedings are in progress."