Secondary teachers have rejected a pay offer from the government and authorised strike action in the first term of next year.
The Post Primary Teachers Association (PPTA) had asked for a single increase of 15 percent and in response the government offered its members a three percent pay increase for three consecutive years.
PPTA president Jack Boyle said teachers voted overwhelmingly to reject the current offer.
He said the sector faces unprecedented, growing teacher shortages and it was becoming harder to attract people into teaching.
"The key part of why we asked for 15 percent is to re-establish relativity with the median wage, such as it was the last time we were able to overcome significant shortages, so fewer people coming in - more of them going, so that number then was 1.74 times on average the median wage.
"That's what we are asking for with that 15 percent, whether its overnight, whether that's over a period of time, that's up to the negotiators.
"We are passionate about our work and feel a responsibility to our students and their families, we have made this decision because the government has given us no other options."
Mr Boyle said a complete correction is needed as the sector has been neglected for a decade.
"We know it's not Jacinda Ardern's government's fault we are in this position - a decade of neglect and underfunding has brought us here, but it is their responsibility to remedy it.
"We need urgent action if we are to recruit, support and retain a home-grown teaching workforce for now and into the future."
Secondary teachers plan to take a one day strike in the first term of 2019.
Education Minister Chris Hipkins said bargaining with the secondary teachers union was not as advanced as the primary teacher union.
"We welcome PPTA back to the negotiating table, which is scheduled to happen next week."
Earlier today, the final two of 35 paid union meetings for members were held and the Wellington and West Coast branches cast their votes.
Aotea College science and chemistry teacher Anna Greaney said the revised offer was pitiful.
She teaches two classes, with 29 and 30 students, and said they were too big.
"In a practical science subject that's not okay," Ms Greaney said.
"It's about not having enough equipment and having eyes on 30 different kids doing 30 different experiments all at the same time.
"Practically, for health and safety, it has got to be an issue."
English and media studies teacher Jordan Murray said the offer was a joke.
"They're not addressing the things that we feel are important: class sizes, the time that we need to be able to do our job properly," Mr Murray said.
"We can get paid as much as they want, but if we don't have the time, we can't do the job properly."
The Ministry of Education made its initial offer to the PPTA in late September.
A new offer was made in November, but it was slammed as being "almost identical" to the first.
The latest offer is worth $405 million and would see all trained secondary teachers' base salaries increase by 3 percent every year for three years.
PPTA president Jack Boyle said it was "a moral failure" and recommended that members voted against it.
"We see that it was last minute, half-hearted and disrespectful," Mr Boyle said.
"Much of what was in the offer - many of the items - lacked enough detail to put it in front of you for genuine consideration."
Wellington regional union chairperson Ahmad Osama agreed, but did not want to pre-empt the vote.
"We've got a shortage of teachers, we've got big class sizes, we do not have enough relievers in the relief pool, and there are many other issues that we are trying to deal with," Mr Boyle said.