"If cars went to Northport, there will be 21,500 more tonnes of carbon emissions which is more than our total carbon emissions now at the Ports of Auckland," Gibson said, citing an environmental study and the port's big drive to cut its carbon emissions.
"What do you think happens to the cars when they arrive at Northport? They would have to be put on trucks to go to Auckland," Gibson said.
He was reacting to Peters' "cast-iron commitment" to move container operations from the port if his party was in a position of influence after the election. Peters wants the port moved by 2027, opening up 77ha of prime waterfront land for public use and the development of a new cruise ship terminal. Peters has long campaigned for a rail link to Northport - vehicles might not be moved on road but rail.
His plan would stop vehicle deliveries by the end of 2019 and free up Captain Cook Wharf ahead of the America's Cup.
Gibson also reiterated the port's already-announced plans to build a parking building on Bledisloe Wharf, saying more details would be out around mid-October when a new study was released.
"That will have all the details but it will be between 1500 and 2000 [carparks]. It will be about four to five levels," Gibson said, having a relatively compact footprint to minimise land use.
"There's a lot of pressure on the waterfront infrastructure."
