The Department of Conservation (DoC) says it has consulted extensively with iwi ahead of a 1080 drop on a mountain in the Coromandel.
The department will drop the toxin over 4500 hectares of Moehau mountain between June and August.
A Ngati Pukenga kaumatua, Awanui Black, says his Coromandel whanau opposes the move, but DoC does not seem to be listening.
He says 1080 will threaten the mountain's waterways and wildlife, and the Government should trust Maori with its guardianship.
However DoC says it consulted local tangata whenua, including at least seven iwi, and other groups such as the Moehau Nga Tangata Whenua Trust.
It says Moehau is home to 260 types of native plants and a number of rare wildlife species, some of which are found nowhere else.
DoC says 1080 is necessary to protect the forest and the native wildlife it supports, because it's at risk from introduced pests, especially possums, rats and stoats.