Te Kawerau ā Maki senior member David Rankin will lay a complaint with police over what he says is Prime Minister Jacinda Ardern's interference in the Ihumātao dispute, he says.
The fight to protect the 32ha land block in South Auckland from a new housing development drew several thousand protesters over the weekend, after an eviction notice was served on 23 July to some of those who had been occupying the land in peaceful protest.
Te Kawerau ā Maki - the iwi considered mana whenua at Ihumātao - remains divided on the issue, with its mandated iwi group known as Te Kawerau Iwi Tribal Authority supporting the development along with a deal with Fletcher Building to have 8ha of land returned to them.
However, the occupation and protest is being partly led by others within the iwi who want the land - some of which is wāhi tapu, including the first market gardens in Aotearoa - protected.
After previously saying the government would not intervene, Prime Minister Jacinda Ardern vowed on Friday that no building would take place at Ihumātao while a solution was being sought.
A senior member of the iwi, Mr Rankin said he would lodge a complaint with police that the Prime Minister used her position to interfere in a legal transaction and as a consequence would deprive the iwi of dozens of homes which Fletchers had contracted to provide to the mana whenua.
"I don't take this action lightly," he said, "but the Prime Minister has directly interfered in a legally valid arrangement, and at great cost to the iwi".
"First, she destroyed KiwiBuild, and now she is destroying Iwi build. Fletchers have agreed to provide 40 houses to our people, which is exactly 40 more houses than the Labour government has managed to provide to us."
Mr Rankin admitted the complaint would make him unpopular, but said there was a bigger issue at stake.
"Ms Ardern has breached the kawa of our hapū, and her actions will leave some of our old people without houses. This is intolerable, and also breaches the law."