Iwi representatives say they will never be able to support the Kapiti Coast Expressway which has been given the green light to be built.
The Environmental Protection Authority on Friday issued the independent Board of Inquiry's final decision approving the controversial road near Wellington after hearing more than 700 public submissions during a 27-day hearing.
Construction of the $630 million four-lane road linking Mackay's Crossing to Peka Peka is likely to start in July this year and is just metres from an urupa (burial ground).
The chair of Takamore Trust, whose members are from the sub-tribes of Te Ati Awa Whakarongotai, says there are fears the sacred site could be disturbed.
Ben Ngaia says the base foundation of the wahi tapu is sand and the road will have to be well built so it doesn't cause vibration which could disturb the dunes.