Labour's plan to build 100,000 houses selling at about $300,000 each is a fantasy, Prime Minister John Key says.
The flagship policy was announced at Labour's annual conference and is the party's answer to the affordable housing crisis.
The government is going to build 6000 homes with 600 of them selling for less than $400,000 at Hobsonville in Auckland.
Mr Key says Labour won't be able to deliver, particularly in Auckland where the affordability problem is much worse than anywhere else.
"They would have to be very, very small or a hell of a long way away," he said.
"This stuff is fantasy land."