A wide-ranging coalition of businesses, social housing providers and other groups has united to push for the implementation next month of Auckland's Unitary Plan.
Fifteen organisations have formed the Coalition for More Homes, to urge the council not to mess with the future blueprint that will significantly boost housing density in the city.
Members include the Salvation Army, the Property Council, Unitec and apartment developer Ockham.
The coalition has written an open letter to councillors saying the Unitary Plan will help tackle what it calls a housing crisis with rising rents, and a shortage of homes, leading to unaffordable prices.
The council meets in a fortnight to begin deliberating on whether to sign off the plan which has been re-written by an independent hearings panel.
Higher density housing has been a hot political issue with some communities in some parts of the city persuading councillors in February to try to water down the council's case before the panel.
"I think it would be ludicrous if they didn't pass it but any one who was in those February meetings will know this council, with an election so close, will try to pull something," said Leroy Beckett of the lobby group Generation Zero, who helped form the coalition.
Independent economist Shamubeel Eaqub said he backed the plan, and described as pessimistic a report suggesting 85 percent of homes built under it will cost more than $800,000.
The computer modelling of one scenario under the development blueprint was highlighted by Labour to show the plan would not solve the city's affordability problems.
Mr Eaqub said the modelling assumed land prices would not change, but the higher housing capacity brought in by the plan would bring greater variety of housing styles and price ranges.
"This is a big game changer for the development industry, and without the constraint of using a large area of land for each house, the outlook is far more optimistic than in the model," he said.
Mark Todd, whose firm Ockham builds mostly three level higher-quality apartments, said the higher density rules were working, as they have already been applied to Special Housing Areas, under the government's Housing Accord in Auckland.
"We've currently got two large scale projects consented as Special Housing Areas under the new rules and there's 200 units with an average price of $630,000," he said.
"At present the new homes being built in Auckland are raising the median house price, but under the new rules a lot can be delivered under the current median house price, lowering the median across the city," said Mr Todd.