A third teachers' union has announced plans for further strike action in the new year.
Members of the NASUWT will walk out next month in an ongoing dispute over pay.
The union confirmed primary teachers will strike on 10 January while secondary teachers will walk out on 11 January.
The Scottish government has previously said the pay demands were "not affordable".
NASWUT is calling for a fully funded pay award of 12% for 2022/23 after rejecting Cosla's improved offer, worth between 5% and 6.85%.
It said the current pay offer tabled amounts to a real-terms pay cut, as inflation reached 10.7% in November.
