A 16 percent pay rise is needed to curb a teacher shortage that has the system in crisis, the primary teacher union says.
Primary school teachers have rejected the Education Ministry's pay offer and will strike next month for what their union says is the first time in 24 years.
Union members will walk off the job between 1.30pm and 4.30pm on 15 August.
The New Zealand Educational Institute (NZEI) is seeking an immediate 16 percent pay rise over two years and improved working conditions.
The ministry offered a salary increase between 6.1 percent to 14.7 percent over three years for trained teachers. This would raise the beginner teacher rate to $50,280 a year, and eventually up to $55,030 in 2020.
Principals would receive between 6 percent to 11 percent, which meant the base remuneration for a principal responsible for 50 or fewer students would increase to $92,873 in 2020.
NZEI lead negotiator Liam Rutherford said salaries were only part of the issue. Teachers were also leaving the profession due to a "burgeoning workload" and lack of resourcing for students with additional learning needs.
The union wanted an offer that addressed pay and workload "so that people stop leaving the profession and people considering it see it as a career in which they can have a reasonable work life balance", he said.
Principals' Federation president Whetu Cormick said there was a teacher supply crisis and the ministry had to address pay and support for teachers.
There had been decline in the number of young people choosing teaching as a career, he said.
Teachers needed additional support for children with special learning needs and difficult behaviour, he said.
"Within special education we've got a dire situation with the increasing number of severe behaviours presented in our schools."
Professional development and psychological support for teachers was urgently needed, he said.
Mr Rutherford said under the ministry's offer 86 percent of teachers would get the smaller, 6.1 percent, increase.
"The 14 percent is for a very small number of people who are just starting their career."
The ministry has said it is disappointed the union rejected the offer and that escalated strike action was being discussed while negotiations were continuing.
The union said some members wanted to extend the strike for an entire day and that could be the subject of a further electronic ballot between now and 15 August.