The chief executive of Te Aitanga a Māhaki says he, and his iwi, have cut off all future engagement with Gisborne Mayor Rehette Stoltz.
Willie Te Aho outlined his reasons in a mass email to council and media on Thursday.
The reluctance to work with the mayor was effective immediately as Te Aho withdrew the iwi presence from the "Tairāwhiti Tomorrow Together" summit yesterday.
"We will work with the council, just not the mayor," Te Aho told The Gisborne Herald.
"As far as we're concerned, [the council takes] the place of the Crown in terms of local government activities, and Te Tiriti o Waitangi means we must be an active partner."
In his email he said he did not dislike the mayor, but found her actions arrogant and disingenuous.
"The Mayor just doesn't get iwi and in my view she never will."
Mayor Rehette Stoltz refused to comment on the specific accusations.
"I don't intend to respond to personal attacks on me. I welcome robust discussions, but the engagement should be respectful.
"My focus is to continue working constructively with Tairāwhiti iwi and all members of our community to ensure our region heals and ultimately thrives.
"While there are matters that need to be discussed, I am not willing to do that through the media."
Te Aho said Stoltz had acted to change the working relationship without consultation.
"Iwi and the council were part of a collective called Rau Tipu Rau Ora to see our way through the tricky times of Covid, and that was the vehicle we used when the cyclone hit last February.
"Without discussing it with her council, she withdrew from [that collective] ... and decided to do her own approach.
"When I notified the mayor that this shocked me, she quickly held a council meeting to inform them of the new approach."
Te Aho said this was just one example of disingenuous acts from the mayor.
"Excluding ourselves from the summit does not mean we do not want unity.
"We just don't want people to think we are an active partner, when we have not been treated like one."
Te Aitanga a Māhaki have also excluded themselves from the Kotahitanga agreement signed in July 2023 - an agreement that the council and iwi would work together in good faith ... but "she's not acting in good faith", he said.
Te Aho also claimed the mayor failed to deliver promised information.
"When you have to follow up someone to get the information that they agreed to provide, that leads you to say, 'Oh, she didn't really mean it when she met with us.'
"She was just saying it to appease us."
Te Aho said: "I won't work with her, which means that we'll look at an independent party that can assist us to achieve a bilateral outcome for our iwi and the council."
LDR is local body journalism co-funded by RNZ and NZ On Air.