Education Minister Chris Hipkins is showing no sympathy for principals who say they've been blindsided by an "unfair" aspect of the teachers' pay deal, which could cost schools thousands of dollars.
As part of the recently-agreed collective agreement, every union member will receive a one-off $1500 payment, but a dispute is brewing over who should pay for the bonus.
In most cases, the Ministry of Education will cover the cost, stumping up for all ministry-funded teachers who belong to a union.
But school boards have been told they will have to foot the bill for any extra staff hired out of their operational funding.
Speaking at Parliament, Mr Hipkins told reporters that should come as no surprise to anyone involved.
"The union should've been well aware of this," Mr Hipkins said. "There's no change in policy around this whatsoever.
"Some schools choose to employ additional teachers over and above their entitlement... it's always been the case that those costs come out of their operations grant."
Mr Hipkins rejected the suggestion there had been any miscommunication from the government.
"If the union either didn't understand or didn't communicate to their members what the flow-on effect was going to be... that's really a matter for the union."
Ministry of Education head of infrastructure service Kim Shannon said it had "always been the case" that schools were required to cover all costs associated with employing additional teachers through their operational funding.
Roughly 1800 schools around the country would be affected, she said.
"For the vast majority... the amount of funding required for the lump sum payments is less than $3,000. This represents half a per cent of their annual operational funding," Ms Shannon said.
"We will work with schools who raise concerns and we'll be providing guidance in our next school bulletin on 29 July."
'Left in the red'
Principals' Federation president Whetu Cormick said he was hopeful the government might still relent and show some discretion.
He said the condition was "unfair" and came as "a complete surprise" to many boards and principals.
"One would've thought if the Ministry were giving the $1500 lump sum to teachers that they were going to foot the bill," Mr Cormick said.
"Boards are going to be left in the red."
NZEI lead negotiator Liam Rutherford agreed some boards would struggle to come up with the "unforeseen" payment and so could be forced to go into deficit or redirect money away from student support.
"Fifteen-hundred dollars is what the government and the Ministry have agreed to. They should be the ones that are wearing that cost, not schools."
But PPTA vice-president Melanie Webber confirmed the conditions surrounding schools employing additional staff were long-standing.
"Principals have always known that they need to comply with all the conditions that are offered in the collective, so it shouldn't be a surprise.
"When you hire additional teachers, you are responsible for providing their conditions and that's just the way it is."
But Ms Webber said the sheer number of schools dipping into their operational funding to hire extra staff showed that the Ministry was not funding enough teachers in the first place.
"Why is it that 7 percent of our teaching workforce is being funded above what is being provided for?"