Teachers at Small Heath school in Birmingham struck on Wednesday of last week. It was workers’ fourth strike in their battle to stop the school becoming an academy.
The NUT, NASUWT and ATL union members held big picket lines at the school’s four entrances.
Parents visited pickets to show support.
Teachers plan a fifth strike for 10 December.
In a statement the unions said the school’s Interim Executive Board (IEB) has “continuously failed” to give assurances that it wouldn’t move towards academy status.
They added that the IEB had “refused” talks at conciliation service Acas.
“We can only conclude that the board has no interest in resolving the dispute,” they said.
Teachers at Alfreton Grange Arts College in Derbyshire struck for three days last week.
The NUT union members are fighting changes to the school timetable that bosses introduced in September.
These involve extending the length of the school day, shorter breaks and nearly doubling the number of lessons.
Over 200 people attended a public meeting over the changes.
Workers were set to strike on Wednesday and Thursday of this week, and on 1,2,3,8,9 and 10 December.
Left candidates Kiri Tunks and Louise Regan have been elected to officer positions in the NUT union.
Kiri Tunks was elected junior vice president and Louise Regan senior vice president.