The Northland Mayoral Forum is set to sign an agreement today to work alongside the Taitokerau Iwi Chairs Forum or Te Kahu o Taonui.
But the agreement is being criticised by a Whangārei hapū group who say the deal threatens hapū rangatiratanga or sovereignty.
The Northland Mayoral Forum comprises three district mayors and the regional council chairperson.
This afternoon, just down the hill from the Waitangi Treaty Grounds and the main Iwi Chairs Forum, the group will sign an agreement to work together with Te Kahu o Taonui - a collection of nine iwi authorities across Northland.
Far North District Mayor John Carter said the signing was significant.
"Iwi and Māori are a big part of our Far North and we've always looked to work closely with them - so this just formalises the fact there's been a lot of co-operation and collaboration over the years."
The Far North District Council and the Kaipara District Council passed motions to endorse the agreement last year - but the Whangārei District Council didn't vote to endorse it.
The agreement seeks to strengthen the relationship between local government and iwi to enhance the cultural, socio-economic and environmental well being of all people.
However, Ngā Hapū o Whangārei Terenga Parāoa doesn't want the agreement to go ahead.
Hapū member Jade Kake said there were major implications for hapū rangatiratanga.
"We would really appreciate it in the spirit of treaty partnerships if our crown partners at least would really take this issue of hapū rangatiratanga seriously and not undermine us."
Ms Kake said the lack of consultation on the agreement from Te Kahu o Taonui itself also presented a problem.
"Our rūnanga has not come back to us as hapu in any kind of meaningful way to ask us if they want to represent us in this way."
Whangārei District Council Mayor Sheryl Mai said any worries about hapū losing their voice in council weren't true.
"The relationship that Whangārei District Council has with hapū is precious and important - a relationship with iwi governance is another important relationship that I personally would like to see."
Ms Mai will attend the signing, as she believes the agreement allows for councils and iwi to build a framework of how to work together.
Chairperson of Te Kao o Taonui, Sonny Tau, did not respond to requests for comment.