Andrew Little says it will take a Labour-led Government a single term in office to fix the housing crisis the Government denies even exists.
Last week the party announced a new policy to relax the rules around Auckland's Metropolitan Urban Limit (MUL), which Mr Little says are artificially driving up prices.
"We said we would change the rules on urban limits so we're not having this arbitrary distinction between properties in Pukekohe selling for $600,000 -- that's just for a section -- then just over the boundary you know, properties actually at a more reasonable sort of level," he told Paul Henry on Monday.
"There's this arbitrary rule that's been created that's just causing this ridiculous inflation in section prices."
Auckland Council says it's a myth that houses can't be built outside the MUL, with land for 23,000 homes already approved through the special housing areas legislation. Another 11,000 hectares -- 1.5 times the size of Hamilton -- will be opened up under the Unitary Plan over the next 30 years too, provided councillors vote for it.
Mr Little says if the council doesn't approve the Unitary Plan later this year, a Labour-led Government will override it and open up the land anyway.
"This is a crisis now. It's not just the homeless and people crammed into homes -- it's actually people who are just doing their best to save for a deposit, can't save, can't keep up with house price inflation, can't get their first home. We've got to help them out."
Auckland Council says it can't release all the land it wants to at once, saying it would cost $17 billion to set up the infrastructure.
In the meantime, like the Greens the Labour Party leader wants Housing New Zealand to use the dividend it would otherwise pay to the Government to build new houses and upgrade existing stock.
While it would take a while to get the "machinery in place" to build new housing, Mr Little says the legislation to fix the housing affordability crisis would be ready "reasonably quickly".
"In a single term, you could do. Absolutely."