College lecturers are to be balloted on whether they would take strike action in an ongoing row over pay.
The EIS teaching union has begun an indicative ballot of members working in the further education sector.
It comes days after members of the union's Further Education Lecturers' Association (EIS-FELA) announced it was in formal dispute with employers Colleges Scotland, claiming it was "extremely disappointed'' with a lack of progress in implementing a national pay deal agreed almost a year ago.
Loading article content
The row over pay initially saw lecturers go on strike for one day in March 2016, with 32 days of action planned if no agreement was reached.
A revised offer from Colleges Scotland was accepted, with staff promised wage rises as well as work between colleges and the union to develop a more ''harmonised'' pay deal across the workforce.
EIS general secretary Larry Flanagan said: "EIS-FELA members have been extremely patient in waiting almost a full year for the delivery of the March 2016 pay agreement.
"However, following the decision last week by college management to attempt to rewrite certain elements of the deal, the patience of our members is now exhausted.
"The EIS does not open any industrial action ballot lightly, but our hand has been forced by the frustrating behaviour of the management side."
EIS-FELA president John Kelly said: "College lecturers across Scotland are deeply disappointed that promises on fair pay made to us by management one year ago have still not been delivered.
"It is simply unacceptable that the management side entered into a pay agreement, then dragged its feet for a year before failing to deliver the deal as promised.
"The EIS-FELA executive urges all further education members to use their vote in this important ballot, and to vote for industrial action."
Colleges Scotland said it wanted to avoid "unnecessary and disruptive" industrial action by lecturers.
A spokeswoman said: "It is very disappointing and inappropriate that the EIS has chosen to ballot its members on industrial action when they have already received a pay increase and good progress is being made in a number of other areas.
"During a period of constructive negotiation, it is an unnecessary step that is not in the interests of students or the college sector.
"While we recognise that the process is taking time, it is nonetheless time well spent.
"Our determination is to resolve what are complex issues as soon as possible, which will create real benefits for students and the whole sector.
"More talks are planned for Thursday March 2 and we will do everything we can to avoid what would be unnecessary, and disruptive, industrial action."