John Key, Helen Clark throw support behind moving Auckland's port north

The call to move Auckland's port further north is gaining traction, with big names throwing their support behind the idea.

Former Prime Ministers Helen Clark and John Key are publicly backing the plan, which would see the port's used-car and container section shifted to Marsden Point.

"The real opportunity to unlock the full potential of a world-class city like Auckland rests with relocating the port. I fully support this sensible initiative," Sir John reportedly wrote on his Facebook page.

"Much to be said for big vision plan for upper North Island NZ port infrastructure: regional development & employment benefits for Northland; releases valuable Auckland waterfront land for higher value purposes for #worldclasscity than Ports of Auckland car park development," tweeted Clark. 

Waterfront 2029 is moving forward with the proposal, and is currently raising funds for its campaign. The Government has yet to make a decision.

"The port has to go, or there will be an endless stream of demands to take up more of the harbour," Waterfront 2029 spokesperson Michael Goldwater told NZME.

Waterfront 2029 is reportedly spending up big on Facebook adverts targeting people in key electorates.

Earlier this year, a working group said there was no point moving the port unless there were strong rail links between the north and Auckland - presently only about 1 percent of freight in Northland travels by train.

"The Government will have to understand the importance of running a proper rail line through to Northland," said chair Wayne Brown.

"The roads in Northland are being hammered by trucks. The best way to get the trucks off the road is on trains."

National Party infrastructure spokesperson Judith Collins is sceptical it could work.

"This concept of [the Ports of Auckland] being shifted up to Northland, which is Winston Peters' and Shane Jones' idea to win a seat, all that does is take around 170,000 jobs that are currently in Auckland, and add enormous cost to freight coming into Auckland as well."

New Zealand First backs the idea.