The head of the Education Ministry insists retention rates are high, despite a move to bring in more teachers from overseas to cover shortages.
Yesterday, the teachers union (NZEI) said a rolling strike would begin on 12 November in Auckland and continue around the country for a week.
The strikes follow a national strike in August, and members' rejection of a second offer last month.
The union said teachers and principals were asking for smaller classes, more resources, and an increase in salaries of 16 percent over two years.
This month, the Education Ministry increased its recruitment budget and raised its target for recruiting overseas teachers, so there will be enough to fill classrooms at the start of next year.
New Zealand Educational Institute's lead negotiator Louise Green said the unprecedented level of industrial action showed there was a crisis when it came to recruiting and retaining teachers.
But Secretary for Education Iona Holsted told Morning Report teacher retention rates were high and the shortage in Auckland is related to churn, or teachers moving between jobs.
"The recruitment into teaching is not really the big problem," she said.
"We've still got very high rates of retention across teaching. We're up in the high 90s in terms of retention.
"The bigger and more important question, I think this an area we all agree on, is that there are big changes that we need to make to how are our schools are staffed, to how we recruit, retain and train teachers."
She said she was confident the teachers' dispute would be resolved and that by next year the shortage would be covered.
"What we do need to do is buy ready-made teachers for 2019 - there's no time to train new ones.
"I'm pleased to say that already we've had around 2300 teachers, overseas teachers and New Zealand returning teachers, express interest in those roles and we've got about 315 who are ready to teach."
She said a work force strategy plan was also in the works - with the first report from it due in December.
But Educational Institute president Lynda Stuart said the official retention numbers were taken from the payroll and did not differentiate between part-time and full-time teachers.
Teachers who dropped their hours were not included in turnover figures, Ms Stuart said.
Principals Federation national president Whetu Cormack told Morning Report the dispute was not mainly about money.
"The unions are asking not just for pay, but we want more time to teach and more time to lead, and we need support to be able to do the very important work that we need to do.
"Yes, there is a roughly 9 percent offer on the table but we don't have any extra time to do the job, and the lack of supports which tie into special education issue."
Primary teachers were offered an extra 12 and a half minutes in addition to the current one hour of 'release time' - time to prepare and plan - but rejected that offer, he said.
Mr Cormack said the current offer could work if teachers also got more time away from the classroom.
"I think if there was more time put on the table and support put on the table, I believe teachers would be then reflecting on what the next step might be."
However, he did acknowledge there was a problem in attracting more people to the profession.
"Over the last 10 years we've had a 40 percent decline in graduates from colleges or of education of university, and so at the moment we don't have enough teachers in front of our young people.
"We're not sure we're going to find those teachers so there's a wider issue around the status of the profession."
Ms Stuart told Morning Report the strike action was a hard decision.
"They don't take this decision lightly at all so for them the one day was actually the better option for most of them.
"I think that our people really want to show their resolve but they also don't want to impact our families and children over two days."
Ms Stuart said the union agreed with the Ministry of Education to urgently lodge an application for facilitation with the Employment Relations Authority.
"We would love to be able to revert the strike. We would love to be able to reach a settlement with the government. At the moment, what we're not showing is the value for our teachers and principals by actually enabling them to do their job. The ask that we've got we think is a fair ask, in a time where there is a crisis in education.
"I think it's around both parties considering the way forward that is going to actually enable the crisis [of strikes] to be averted."
The Ministry of Education said it and the union will urgently seek facilitated bargaining, to help reach a settlement for primary principals and teachers.
Ms Stuart said while strikes will go ahead, "we have agreed to continue to try to seek a resolution.''
Education Minister Chris Hipkins said there was still a lot of water to go under the bridge before the strikes, and the government was pleased the union and ministry were seeking facilitation.
Rolling strike dates:
- Wider Auckland region - Monday 12 November
- North Island (except Auckland and Wellington) - Tuesday 13 November
- Wider Christchurch region (including Ellesmere, Ashley, Mid-Canterbury, Malvern, Hurunui and Aronui Tomua Waitaha) - Wednesday 14 November
- South Island (except wider Christchurch) - Thursday 15 November
- Wider Wellington region - Friday 16 November