Workers began a three-day strike at The Village School in Brent, west London, on Tuesday of this week. The action, by NEU union members, is against a plan to turn the school into an academy.
It comes ahead of a planned strike by three schools in Newham on Thursday over the same issue.
The school could become part of a Multi-Academy Trust (MAT). The strikes have forced the local Labour council to oppose the academy plan.
Barry Gardiner MP held a packed meeting of parents, staff and local residents before half term.
Council leader Muhammed Butt backed the strike.
Workers came from Woodfield school, which is already an academy. They said conditions had got worse since academisation.
Governors are set to meet on Wednesday 28 February to decide whether to go ahead with academisation.
Workers plan a two-day strike from Tuesday of next week to coincide with the meeting and pile pressure on governors to oppose the plan.