"It was public land, it was used by the public, it had promise to be a public piece of land for all of New Zealand for all time if we could have turned it into the park, walking track and lookout, and interpretive centre that we wanted to do."
He said 109 locals voted unanimously at a meeting to look at legal action.
Joining him in the battle is Te Kapotai hapu Māori committee chairman Peter Clark.
"I would like to see ... the whenua be given back to its rightful owners who are wanting to work in a partnership with all the local community to build it into a park, for the common use of the community - not to be sold off to some developers to make it ugly and make money from it."
He said descendants of the four hapu who whakapapa to the area - Te Kapotai, Ngati Hine, Te Roroa, and Ngati Manu - also wanted a pou on the site to recognise Pumuka, who was killed at the battle of Kororareka in 1845.
Te Runanga o Ngati Hine deputy chairman Pita Tipene said it should have been consulted as a claimant in the area.
"For FNH to be dealing with investors to develop land and not formally tell Ngati Hine - we're very angry and frustrated over that lack of information."
FNH said the Ōpua community had every opportunity to have their say, with chief executive Andy Nock saying the initial consent application was publicised in May 2018 on Facebook; in the local newspaper; on its own website; and with the community group Love Ōpua.
He said there had not been a single submission or contact from anyone in the 19 months since.
Nock said he was saddened to hear that Ngati Hine had felt the lack of engagement with them was disrespectful, and would be raising the matter with them directly.
A bushland area of 2800sq m would be set aside in the middle of the development, he said. The firm would also be installing a walking trail to connect with the marina precinct and a planned play area. - RNZ
