Chief executive Ken Shirley said most goods that arrived at the port were consumed in Auckland or markets south of the city. That made the extra cost of transporting them from Northport "completely nonsensical".
"We have heard for a while now how enthusiastically interventionist New Zealand First is on the economy but legislating to force goods from one port to another is next level - it is pure Stalinism.
"The huge investment that would be needed to the infrastructure of Northport and the transport links from there to Auckland are complete folly, we might as well ask taxpayers to stand around burning $100 bills."
Shirley, a former ACT MP, said he had seen many bad election policies but "this one takes the cake".
"If Labour or National entertain this kind of rubbish during post-election negotiations then they deserve the full wrath of the electorate that will surely follow."
Labour leader Jacinda Ardern this morning told the Herald that Labour had committed to making a decision about the future of the port which is in the best interests of New Zealand.
Asked if Labour would respond to Peters' "cast-iron commitment" to move the port to Northport at Marsden Pt by 2027, Ardern said there a range of options that needed to be given due consideration.
"There is no reason why that one should not be part of the mix, but we do need to make that decision in the best interests of the whole country, not just looking solely at issues of regional economic development. It has to be the best for all of us," she said.
Labour, Ardern said, was open to the discussion of moving the port long-term and had stood against port extensions that had led to the longer term discussion.
Ardern wanted to see imported cars gone from Captain Cook Wharf.
"It's a ridiculously expensive carpark," she said.
Stop Stealing Our Harbour this morning welcomed the "fantastic news today that could save our harbour from Ports of Auckland's relentless expansion and help transform Auckland into one of the great waterfront cities of the world".
"This is the first time any major political party has made such a visionary commitment to the future of Auckland's waterfront. With polls telling us NZ First will be the kingmaker after the election, this could be a once-in-a-lifetime chance for Aucklanders to permanently resolve the port issue," Stop Stealing Our Harbour said in a posting on Facebook.
"Whether NZ First is your cup of tea or not, Winston Peters deserves acknowledgement and applause for tackling one of Auckland's biggest opportunities head-on. He is one of only a few politicians to strongly and openly advocate moving the port and revitalising Auckland's waterfront. His proposal could free our beautiful waterfront for generations to come.
"We are not port experts, so we can't say whether Whangarei's Northport is the best option or not or whether the transport links to Whangarei are workable, but we can cheer on ideas that advance transforming Auckland's great waterfront.
"So let's all enthusiastically show our support to anyone who has the courage to start discussing innovative ways of solving the port problem. Today it's Winston Peters who has thrown his hat in the ring and we should all acknowledge his vision," the lobby group said.
Central Auckland iwi Ngati Whatua Orakei this morning reiterated its support for moving the port. Spokesman Ngarimu Blair said the port was incompatible with a well-functioning and attractive CBD.
"New Zealand First's proposal... would be great for Auckland and Northland. Our Te Tai Tokerau relations will relish such a move north and rightly so," Blair said.
Blair said Ngati Whatua had had initial discussions with potential partners to invest in and move the port, such as Waikato-Tainui, since Goff floated the idea of selling in May this year.
"This is the kind of investment that iwi can not only participate in but lead, as we have a clear and vested interest in Aotearoa and our communities. We are prepared to lead such discussions and will wait for the outcome of the election to progress those further."
Blair said Ngati Whatua Orakei remained totally opposed to any port extension further into the harbour, and is "bemused" at the council's current proposal to extend Captain Cook Wharf.
Auckland Mayor Phil Goff told Newstalk ZB he thinks most Aucklanders would like to see the port moved from the CBD. But he says it's a big asset for the city and should probably remain within city bounds.
Peters wants the relocation completed by the end of 2027 - opening up 77ha of prime waterfront land for public use and the development of a new cruise ship terminal. His plan would stop vehicle deliveries by the end of 2019 and free up Captain Cook Wharf ahead of the America's Cup.
