Any further commercial expansion of Auckland's port would be halted under legislation put forward by New Zealand First.
Winston Peters said the port company was acting "like some sort of warlord" in the face of strong public opposition.
NZ First has now lodged a Bill in the members' bill ballot. If it is drawn and eventually passed into law, it would limit any further expansion of the port.
"We have moved quickly with a Bill to freeze the size of the port and push any future growth to other ports," Mr Peters said.
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"The Waitemata Harbour Protection Bill, if passed into law, will end the controversial wharf extension plans of the Ports of Auckland and ensure environmental and recreational protection for the harbour. In doing so we will be saving a recreational gem for Aucklanders."
This week the Herald revealed that a secret briefing of Auckland councillors was presented with four "immediate options" to resolve the public outcry and stand-off between the council and port bosses over the extensions.
The options include allowing the port to proceed with the extensions and the council sticking to its guns for Ports of Auckland to down tools while a year-long port study is done.
But it is understood that councillors are being urged to accept one of two compromise options. The first is to go ahead with the eastern extension and reduce the western extension from about 92m to 40m. The second compromise is to only build the eastern extension and wait for the port study and new planning rules in the Unitary Plan before considering the western extension.
Mr Peters, who was sworn-in as Northland's new MP this week, said Whangarei's Northport, as a natural harbour that does not require dredging like Auckland, was a viable alternative.
"Northport could become a leading port. New Zealand First wants investment in the rail link and sees the development cost as necessary to build a future asset."