Teachers and principals around the country have started voting today on whether to strike for a full day on August 15.
Members of the New Zealand Educational Institute - Te Riu Roa union will vote by secret ballot to extend the initial three-hour strike to a full day.
Teachers are asking for more time to teach, more support for children with additional learning needs and a pay jolt to stem the teacher shortage.
The union's national executive, Lynda Stuart said on Friday that the union approved a secret online ballot of members to vote on the issue.
"Over the past few weeks, members have told us of their resolve to send the strongest possible message to the government about the crisis facing schools. We have listened to members and will now ask them to vote by secret ballot to extend the proposed three-hour strike to a full day," she says.
"It is obvious that teachers are committed to working for change to ensure all children get quality teaching and learning. They are saying that it's time for them to be valued for the professionals they are, that we need to attract and retain teachers, have more time to teach and to have truly inclusive schools where all children can learn and thrive."
The ballot will run for a week from this Wednesday July 25.