Auckland Mayor Phil Goff says it's not a question of if the Ports of Auckland should be moved, but where.
However, any move would cost about $10 billion and if the council had that sort of money it would be better spent elsewhere.
Speaking at an NZ Herald Premium debate tonight on the future of Auckland's port, Goff said freeing up the waterfront land created an "enormous opportunity" for the city.
"The first step is where we move the port to, which has local, regional and national significance."
Goff joined panellists Transport Minister Michael Wood, Shane Vuletich of Fresh Info and Julie Stout of Urban Auckland for a debate at the SkyCity Theatre.
They discussed how a cornerstone of the city's economy was suffering capacity constraints, imposing a massive burden on the motorways and occupying land that could be put to better use.
Shipping, economic costs and opportunities, the environment and freight were at the heart of tonight's event.
The debate turned to findings in the 2019 Upper North Island Supply Chain Study, which recommended the managed closure of the Ports of Auckland and the development of Northport.
But Goff said he, Treasury and the Transport Ministry all had big problems with that study, which had failed to properly examine alternative locations such as Manukau.
"This was a conclusion looking for a justification."
Moving the port would cost $10b or more, which would require central Government involvement, Goff said.
"They're not going to leave us with 100 per cent ownership. So a new port would have us as a minority shareholder. And frankly if it I had $10b, there are a lot of other things I'd rather buy than a new port."
Vuletich said the supply chain study, which he had worked on, had emphasised a "rail-dominated freight system to get containers off the road".
It had examined Manukau "but that was discounted very early due to extreme challenges".
"We have greater aspirations for South Auckland than as a dumping ground for containers."
Wood said it was important to keep the bigger picture in mind and the port issue should not be a process led by regional interests.
Ports had a primary responsibility to make a return to shareholders and a "conversation" was needed on that, he said.
A freight hub being built on the outskirts of Hamilton was a road, rail and significant industrial infrastructure project, bigger than the Auckland central city.
"That's the kind of thinking we need," Wood said.