National's Tukituki executive has written a letter to Prime Minister John Key and party leaders, claiming the stance on the Havelock North kura kaupapa is harming the party's image.
The letter, released under the Official Information Act, states an "uncompromising stance" was causing "anger, confusion and disillusionment" among longtime stalwart National Party supporters in the region.
It was sent to key figures including Education Minister Hekia Parata and Tukituki MP Craig Foss in February.
"National needs to be rational in its decision making and this kura kaupapa issue has resulted in a distinctly irrational decision," the letter reads.
"The present uncompromising stance of Hekia Parata over this matter may well be the catalyst that causes a big defection from National, Tukituki, in the 2017 election."
The executive further said the "catch cry" being echoed on the streets of Havelock North and in the media was that the National Party did not listen to people in the regions.
"Do we want a repeat of Northland?" they asked, referring to Winston Peters taking the National Party stronghold in last year's by-election.
Tukituki electorate chairman Kevin Trerise said the letter was the feeling of the executive at the time "and it was written in that way and to support the MP [Craig Foss], our local MP".
"There has been a fair bit of movement since the letter was written."
Mr Trerise said the executive was informed by Mr Foss that the letter had been received and Ms Parata's office replied, saying comment would be made at a later date. He said while the minister had yet to respond to the letter, both she and Mr Foss "work closely on a daily basis".
Mr Foss said he understood the executive had strong views on the kura kaupapa, "as do many other people".
"That's why, from day one, I've been asking for more information and presenting constituents' concerns to the decision-makers," he said.
"The committee has supported me as the local MP for many years and its letter was an extension of that support."
Ms Parata did not respond directly to the contents of the letter, simply saying "education decisions are not political".
"They are made on the basis of what is in the best interests of children's education and wellbeing," she said.
Labour's Tukituki spokeswoman, Anna Lorck, agreed with the local National Party executive's claim that the Government was not listening to regional New Zealand.
Mr Foss said the Ministry of Education's decision to take another look at its plans for the Arataki Rd site was a positive move for the community.
"This is not about me or who knew what and when, it's about getting the right result for our kids and their families, he said.
"That's always been my focus."
Ms Parata said any future decisions about the location of the kura would depend on the findings of the ministry's current environmental assessment of the site, commissioned to look at the odour issues from the neighbouring mushroom farm.
Despite what was written in the letter about the kura fracturing the party's local support base, Mr Trerise claimed the vote for National and the personal support for Mr Foss was still strong.