Tauranga city councillor Catherine Stewart has stepped down from her role as deputy chair of the wastewater management review committee.
Ms Stewart removed herself from the role due to Treaty of Waitangi principles.
Papamoa hapu Nga Potiki said the deputy should be a tangata whenua member.
The justification was membership should be in accordance with the Treaty of Waitangi, with partnership meaning equal standing and decision-making powers.
"An immediate discrepancy is the chairperson and vice-chairperson are elected members of Tauranga City Council."