A group of men have launched a sexual discrimination case amid claims their female counterparts are getting paid more than they do.
Twenty six workmen from the University of Wales, Trinity St David, argue they have been underpaid by an average of £4,000 a year from 2007 to 2013.
A group of 18 of them, who include tradesmen and carpenters, today began their case at an employment tribunal in Cardiff.
A hearing was told they were at grade three on the university's pay scale - but a dispute arose when their contracts changed.
Previously, the men had been on a minimum 45 hours per week contract until new regulations sought to standardise all workers' contracts to a 37 hour working week instead.
Fearing the drop in hours would cause problems among the workmen, university bosses decided to stick to a new "framework" but guarantee them the extra eight hours and class it as overtime pay.
However when the new contracts changed, the men said they realised their hourly rate was less than women who were on the same pay scale.
Tradesman Robert Cooze, who works on Trinity St David Swansea campus - formerly Swansea Metropolitan University - insisted he and his co-workers had a valid case.
Mr Cooze, 50, who lives in Mayals, faced claims from the university's legal team that their claims were a "startling proposition".
QC Peter Wallington asked him: "You hear a great deal about discrimination of women....but it's very rare to hear about deliberate discrimination against men.
"Are you seriously asking us to believe that you were discriminated against because you are men?"
Mr Cooze replied "Yes I am".
All the men were originally employed by Swansea Metropolitan University, which merged with the University of Wales Trinity Saint David in August last year.
Mr Wallington described the case as a "complex" one, but insisted the university had a defence under the Equality Act.
The university is not disputing the difference in pay between its Grade three workers, but denies the reason is because of their gender. It says it is coincidental the workers happen to be of different sexes and is more to do with the fact the tradesmen's demands over their 45 hour working week.
Among those giving evidence today was senior university official Professor David Warner.
In a statement read into the record, he said: "It should be noted that by maintaining the 45 hour week by the way of guaranteed extra time of eight hours, all ancillary workers received both an increase in salary and enhancement to their pension entitlement."
However, case presenter Caroline Musgrove said officials from the then Swansea Metropolitan University had signed up to a national framework agreeing to be "fair" and "transparent" on pay yet had failed to implement it.
The case continues.