A final working group report says Auckland's current port operations are "no longer economically or environmentally viable".
It comes as the Government is considering moving the port to Northport, near Whangārei.
This new report means the massive transition could begin by December of next year, with completion of the move as early as 2029.
The report details how the freight operation at Ports of Auckland is no longer economically or environmentally viable. And if Auckland and Northport can't reach a commercial agreement within 12 months, the report suggests, the Government should introduce new legislation to force the move.
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Auckland Mayor Phil Goff wanted compensation if the port moves, but 1 NEWS understands the final report says the development potential of 77 hectares of prime waterfront land is compensation enough.
If it goes ahead, it will be the largest infrastructure project in New Zealand history, costing $10 billion dollars.
Along with a massive road upgrade, a new 18-kilometre rail line would be built to connect Northport to the main trunk line between Auckland and Northland.
Northwest of Auckland, a new freight distribution terminal would be built, and a new stretch of line would run through West Auckland, so no big freights trains need to come into the CBD.
Ministers Shane Jones, Phil Twyford and Grant Robertson were approached by 1 NEWS for comment.
However, as they only received the report at the weekend, they declined to comment today.