A group working to preserve the Waitakere Ranges says a proposed housing law gives the Housing Minister too much power and leaves areas of native bush vulnerable to housing development.
The Housing Accords and Special Housing Areas Bill would allow the Government to make unilateral planning decisions if agreement cannot be reached with local councils.
The Waitakere Ranges Protection Society fears the foothills of the ranges could be a target for major development.
The society's president, John Edgar, says that area is currently protected by the Heritage Act, which overrides the Resource Management Act.
He is concerned the new legislation removes the safegards and allows the Government to designate the foothills a special housing area.
Submissions on the bill have been heard and the select committee is due to report back to Parliament on 27 July.