Federated Farmers and anti-GE advocates are squaring up in the High Court over the right of communities to have a say in the use of genetically modified organisms (GMOs) - especially crops.
The national farming lobby is challenging an Environment Court ruling from May 2015 that regional councils do have such a right under the Resource Management Act (RMA).
It is arguing that councils cannot use the RMA to control the use of GMOs.
It says central government passed the Hazardous Substances and New Organisms Act expressly for that purpose, and the Environmental Protection Authority (EPA) is the sole regulator of GMOs.
The farmers argue that parliament cannot have intended for local councils to duplicate that job, or thwart the authority of the EPA.
Their appeal, which is being heard in the High Court at Whangarei this week, is a bid to overturn a decision by the Environment Court's Judge Newhook, who found that councils did have a role to play in the use of GMOs.
He found all resource use was governed by the RMA unless specifically exempted and, since regional councils were charged with the sustainable management of resources, they must therefore be able to consider the social, economic and ecological effects of genetic modification.
GE Free Northland spokesperson Zelka Grammer said, since that decision, councils up and down the country have been responding to community pressure to limit or ban GMOs.
"Hastings District Council, for example, since Judge Newhook's decision in our favour, they've proceeded with their district plan and they have banned everything," she said.
"They have banned any outdoor GE experiments; any releases for a period of 10 years. And there was very strong support in that district for that protection."
EPA 'should not be able to be undermined'
In Northland, farmer and former regional councillor Ian Walker said local councils lacked the scientific smarts to make those sorts of decisions.
Mr Walker who fought to keep genetic engineering off the Northland council's agenda said the anti-GE lobby was holding back production and hurting the economy.
"None of our councillors has a science background," he said.
"The EPA is the agency that does have the scientific knowledge to control GMO releases, and it should not be able to be undermined by councils," he says.
"There are GM grass strains being trialled overseas at the moment that could help us weather climate change," Mr Walker said.
"They would reduce the impact on the environment and stand up to drought and flood. But they're effectively banned in this country and we may never get them."
Organic growers concerned
The Soil and Health Association, Whangarei District Council, the Northland Regional Council and GE-Free Northland are all represented at the appeal hearing.
Both councils are taking a precautionary approach to GMOs in their policy statements, but it is the Soil and Health Association that is footing the bill for the court case.
The association's co-chair, Marion Thomson, said donations had poured in from around the country - many of them from organic growers worried that GMO crops could ruin their livelihoods
Local communities should be able to control where GMO crops could be grown, she said.
"There is no tolerance for GMOs in an organic production... If someone's growing GMO crops next to an organic property and it's contaminated, they lose their organic certification. So it's pretty serious, for a business."
Mana whenua in the north are also taking a close interest in the appeal.
Dr Benjamin Pittman, of Ngāti Hau, said GMOs presented a unique problem for Māori.
He said plants and animals were seen as having their own whakapapa, or genetic lineage, and messing with that went against tikanga, the sense of what was right and good.
"We know that plants evolve and change over time through natural causes," he said.
"The problem is this human intervention. At the very least, there needs to be discussion about it and not just a blanket decision, like this is how things are going to happen."
The GE appeal hearing winds up this morning in the High Court in Whangarei, with submissions from Soil and Health Association lawyer Dr Royden Somerville QC.