Teachers at Copland Community School in Wembley, north west London, were set to strike on Thursday of this week.
The workers are fighting plans to turn the school into an academy.
ATL, NASUWT and NUT union members were set to join the walkout.
nNUT and NASUWT union members at Westwood Girls’ College for Languages and Art in Croydon, south London, were set to strike on Wednesday of this week.
The walkout is over excessive observations at the school. Workers plan further strikes on 6 and 18 June.
GMB and Unison union members at Uplands Junior school in Leicestershire are balloting for strikes over job cuts.
NUT union members at the school have already voted for strikes. School management plans to cut eight teaching assistant posts at the end of the summer term.
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