Unions have rejected the latest pay offer for school janitors and pupil support staff in Scotland's schools.
Council body Cosla said the two-part offer would give workers at least a £1,929 increase in annual salary by 1 January 2024.
Strikes are due to take place in a fortnight that could close three out of four schools.
The Unison union said Cosla had until 20 September to "significantly improve" the offer and prevent walkouts.
GMB Scotland dismissed the latest offer as "far too little, far too late" to avoid the upcoming strikes.
The other major council union, Unite, is still to respond to the new pay offer.
Cosla insisted "the simple fact of the matter" was that there was no more money available for pay without real cuts to jobs and services.
The proposed strikes on 26, 27 and 28 September will also involve catering and cleaning staff in schools and early years centres.