The Ministry of Education says the Post Primary Teachers Association should return to the bargaining table instead of striking.
The union revealed on Monday its members last week voted for industrial action including a one-day strike some time in the next two weeks and further stoppages in the fourth term.
Talks between the ministry and the PPTA stalled earlier in August. The union had claimed a pay rise of 4%, while the ministry offered 1.5% this year plus a further 1% next year.
PPTA president Kate Gainsford says working conditions are also an issue.
However, the ministry says its offer is fair in the current economic situation.
It says it must take pay parity into account, which ensures primary teachers get the same pay rises as secondary teachers, and the union needs to prioritise the 46 claims it has made in collective agreement talks.
The ministry says every 1% increase to the Government's entire payroll for teachers and principals costs about $50 million.
The PPTA says teachers are insulted by the Government's response to their pay claim and voted overwhelmingly in favour of industrial action at stopwork meetings last week.
Union president Kate Gainsford told Morning Report the strike is not just about the amount of money being offered by the Government, but is also in response to a lack of response by the Ministry of Education to other parts of the claim.
The one-day strike is likely to occur on 15 September, but the timing could change.
Pay claim legitimate, say principals
The Secondary Principals Association says teachers need to be offered more in pay talks if recruitment and retention problems are to be solved.
Association president Patrick Walsh told Nine to Noon that their pay claim is legitimate.
He said the morale of teachers is low and it could fall further if a reasonable settlement does not happen, making retention and recruitment problems worse.
However, he said that if the strike lasted more than one day, it could alienate students and their parents.
Minister 'disappointed' at strike plans
Education Minister Anne Tolley says she's disappointed that secondary teachers plan to strike.
Mrs Tolley says the result of the vote is extremely disappointing.
She said parents would not welcome the industrial action and urged the PPTA to go back to the bargaining table.
Mrs Tolley said further comment will have to come from the Ministry of Education's negotiators, but are yet to be formally advised of the result of the union vote.
Prime Minister John Key says he is not expecting secondary school teachers to find much support from parents for their industrial action.
Mr Key says the PPTA's decision is very disappointing and parents will find it disruptive and unreasonable.
He says it would be unfair to give teachers a pay increase of 4% when everyone else is settling for less than 2%.
