A working group looking at the future of Ports of Auckland has come down in favour of moving it to either Firth of Thames or Manukau Harbour.
However, this would be a long-term project and in the meantime the existing port would be beefed up to make sure it stayed economically viable.
That would include adding 25m to Bledisloe Wharf at Auckland Harbour, expanding the port's capacity to allow it to receive a further, very large, ship.
But this would not be on reclaimed land and the piles that would hold up an extended wharf could be removed later.
Mayoral candidate and former Labour leader Phil Goff said more study was needed, which could take decades. He supported giving the public more access to the waterfront.
"I'd like to see Aucklanders get access to the waterfront back and I'd like to see that waterfront transformed into a great public space area, great residential housing and high-value added commercial activities."
Rival candidate Vic Crone agreed. "When you think about Wynyard Quarter all the way around to Judges Bay, I mean that would be an incredible statement of Auckland on the world stage."
Transport Minister Simon Bridges, however, didn't think moving the port was realistic.
The enlarged wharf would still be far smaller than a controversial proposal last year, which was opposed by protesters and blocked by a court verdict.
The aim of the extension would be to keep Auckland's port, under its current configuration, economically viable - since that would be necessary to create a business case for eventually moving the port elsewhere.
RNZ News has learnt that a move could cost between $4 billion and $5.5bn, but could be higher depending on how much connecting infrastructure needs to be built.
Sale of the real estate beside the Auckland wharves would fetch a far smaller price - perhaps $1bn, according to early estimates.
The working group reached consensus on keeping Auckland viable in the short-term but moving it long-term to either Manukau Harbour or Firth of Thames.
Manukau Harbour was the most favoured option, preferably at Puhinui, near Auckland Airport.
The working group accepted recommendations that this was practical, despite a notorious sand bar at the harbour mouth which had caused many tragedies in the past - including New Zealand's worst-ever shipwreck, the Orpheus.
The group accepted recommendations that dredging of Manukau Harbour and its bar was feasible.
There have been suggestions that a financial arrangement with iwi would make a state-of-the-art, brand new port in the Firth of Thames viable, but expensive roading and rail upgrades would have to be paid for.
Shipping companies and iwi were thought to oppose a big new port in Manukau Harbour, while a big port at the Firth of Thames could be crowded up against Port of Tauranga.
Those problems stemmed from worries the present Auckland port could not expand without incurring public opposition, but not changing would erode its financial position compared with other ports.