Teachers' representatives have called for a ballot on industrial action if Scottish education authorities press ahead with controversial changes to their working conditions.
EIS union members made the call at a special general meeting on the issue.
The McCormac Review, commissioned by the Scottish government, recommended reforming the ten-year-old McCrone deal.
The plan could see the end of teachers working a fixed 35-hour week.
It also called for more flexibility over the duties teachers can carry out.
Stirling University principal Prof Gerry McCormac, who headed the review, suggested it was inappropriate for teachers to have lists of duties such as photocopying and filing that they could not be asked to do routinely.
Many teachers exceed the 35-hour week and perform tasks they are not required to, but they want these clauses retained in their contract to offer some protection against a potentially heavy workload.
There is also strong opposition to a recommendation that teachers should stay on the premises during the school day even if they do not have classes.
Negotiations on the McCormac proposals are due to start later this month.