Local bodies from Auckland to Cape Reinga are pushing ahead with moves to keep their regions GE-free.
The Environmental Risk Management Authority has responsibility for approving field-trials of genetically modified crops and animals.
However, seven northern councils, including Auckland City Council and Auckland Regional Council, say they cannot rely on ERMA to protect their ratepayers from risk.
The councils say that if a GE trial goes wrong, councils and neighbours could end up paying for damages and costs.
The councils have commissioned a phone poll to gauge community feeling on the issue, and say if there is support they will move to ban or regulate GE trials within their boundaries.