Auckland Mayor Len Brown has the numbers to push ahead with filling in more Waitemata Harbour, a senior council source says.
The council has started a meeting to vote to "support in principle" two options by Ports of Auckland to reclaim more of the harbour for port operations.
The ports have pulled back from earlier plans to push 283m into the harbour for 22ha reclamation.
This followed a campaign by the Herald last year against further reclamation.
Groups for and against the latest plans will address the Auckland Plan committee.
A council source said a vote on the issue was a done deal.