Staff at 20 Scottish colleges are striking today in a dispute over pay.
Unison said further education employers had “failed to offer any acceptable way forward” for 2,300 union support workers.
The union said its members had been treated as “second class citizens” after being offered a flat rate pay rise of £230 compared to £450 for teaching staff.
Lecturers went on strike for a day in March earlier this year which led to the £450 settlement.
— Dundee UCU (@DundeeUCU) September 6, 2016
Chris Greenshields, chair of Unison Scotland’s further education committee, said: “The message is loud and clear that Unison members in the sector are fed up being treated as second class citizens and the value of their contribution to the sector demeaned.
“We have been offered an annual pay rise which is about half that which the same employers thought fair and reasonable, and affordable, for teaching staff. We are simply asking for fair pay.”
A spokeswoman for Colleges Scotland Employers’ Association said the majority of colleges would remain open, and urged the union to rethink the strike.
She said: “We would not want to underestimate the impact that this and further strikes could have on students who are just starting courses or continuing their studies at the next level.
“Unison is demanding a flat cash increase of £450 for all support staff for 2016/17, however their members are already getting a good deal which exceeds public sector pay and which is comparable to the deal already accepted by lecturers.
“Their demands come at a time when many Unison members received above inflation pay rises earlier this year, on top of a reduction in working hours and additional holiday leave. Unison’s demands are not financially sustainable going forward.”