Tai Tokerau iwi say Northland's environment is being put at risk because the regional council has no plans to manage and control genetically engineered organisms.
The tribes say the council is wrong to to leave such provisions out of its proposed new resource management policy.
Te Rarawa environmental manager Abe Witana says enforcement will be left to one agency - the Environmental Protection Authority.
He says having a sole protector and gatekeeper will fail Maori and all New Zealanders - and ratepayers will have to pay to fix any problems if things goes wrong, such as the cross contamination of crops.
Organic farmer Percy Tipene says genetic engineering is an affront to tikanga Maori, whakapapa - and is a breach of the Treaty of Waitangi.
Tai Tokerau tribes are demanding robust local control.
Submissions on the council's regional policy statement can be made until Monday evening.
