A union is holding a special meeting which could decide to ballot teachers for strike action over pay.
A special meeting of the EIS teaching union’s council will take place in Edinburgh on Saturday.
Members have been told it will decide on the next phase of a campaign for a 10% pay rise.
An update to members said this “may well be a move to a statutory ballot for industrial action”, unless the Scottish Government and council umbrella body Cosla provide further concessions in pay negotiations.
Education Secretary John Swinney has said an updated offer from the Government and Cosla is “a better deal than for any group of public sector workers in the UK”, but it was rejected by the teachers’ side of the negotiations earlier this week.
Teaching unions claim teachers’ pay has fallen 20% in real terms in the past decade and a significant increase is needed to show teachers they are valued and to help boost staff recruitment and retention.
In an update to members, the EIS stated: “In an attempt to agree a settlement, the teachers’ side has proposed options which would improve the offer for all teachers, but it remains to be seen if these will be taken up.
“We confirmed our willingness to meet again, as and when required.
“Members have been extremely patient over a pay claim which was due last April. Clearly, that patience has its limit.
“A special EIS council meeting has been arranged for this Saturday, January 12, to decide on the next phase of the campaign, which may well be a move to a statutory ballot for industrial action, if there is no further movement from Scottish Government and Cosla.”
Mr Swinney said the pay offer “would see teachers receiving a minimum 8% increase between January 2018 and April 2019”.
An earlier offer, which Mr Swinney said at the time was the “best available” and would give most teachers a rise of between 5% and 11%, was rejected by the teachers’ side of negotiations in September.
The following month, more than 20,000 people marched in Glasgow in support of the teachers’ pay demand.