The Auckland Regional Council may take legal action against the Government as it steps up its fight against plans to make the super-city smaller.
A parliamentary select committee on Auckland Governance has recommended cutting the Rodney District in half and shaving off part of Franklin before the region's districts combine to make the super-city.
The committee recommended that part of the Rodney District be governed by Northland, while a part of Franklin should be under Waikato control.
The regional council has unanimously agreed to oppose the plans, signing a letter of protest to Prime Minister John Key and launching a petition for ratepayers.
Regional council members describe the boundary changes as bizarre, silly or "from the left field". They believe the plans are divisive and leave sensitive areas open to abuse by developers.
ARC chairman Mike Lee will not be drawn on what further legal action the council may take, but says he would rather work with Mr Key.
"(Mr Key) remarked the other day that if there was a strong and unified expression of public concern on opposition, he would listen. And I believe he will listen - I hope so."
Mr Lee says he wants the Prime Minister to make good on his promise to listen to Aucklanders over the issue.
"The message we want to get across to the politicians in Wellington is that this is totally unacceptable to the people of greater Auckland."