But Environment Minister Nick Smith came out saying the Government would review the "appropriateness of councils being involved in regulating GMOs", prompted by advice over an Auckland Hospital liver cancer vaccine trial involving a GMO.
With the RMA providing for existing-use rights, and because the liver cancer trial is under way, it could continue but could not be expanded.
"The new Auckland Unitary Plan prohibits the release of any GMO and would not allow any such future medical treatments," Dr Smith said.
"It does not make sense for local councils to duplicate the role of the Environmental Protection Authority [EPA]. I have been advised by the EPA that the use of GMOs in modern medicine is growing and that they expect further applications."
Options include changing the law to clarify that controls on GMOs are determined by the EPA, not councils, he said.
Martin Robinson, GE Free Northland spokesman, said Dr Smith was "trying to obfuscate the issue" by invoking research in a medical laboratory as a reason why local authorities should not be allowed to ban outdoor GMO trials and other use.
He said the High Court ruling backed up a careful, collaborative process that had wide-ranging support.