The revised figures follow a testy exchange last week between Mr Brown and new Housing Minister Dr Nick Smith over the best way to provide about 13,000 new homes a year in Auckland.
Dr Smith vowed to break the "stranglehold" of the council's policy of containing urban sprawl - a policy he says is "killing the dreams of Aucklanders" by driving up house prices.
The minister wants to open up more land outside the existing metropolitan urban limit to peg back land prices which, he said, were the biggest factor putting home ownership out of reach of many.
Mr Brown hit back, saying Dr Smith was advocating a flawed Los Angeles model of "suburban sprawl" going back to the 1940s and 1950s.
The mayor said the new unitary plan - a draft is being released on Friday - provided for a balanced approach of intensification of existing land and releasing new land to house a further million people in Auckland over the next 30 years.
Councillor Dick Quax said Mr Brown had proclaimed to all who would listen that Auckland had 15,000 sections ready for houses to be built on "right now".
"The mayor is now having a big helping of humble pie as he acknowledges that there are just 2000 sections ready for construction to begin.
"What this means is Auckland runs out of land to build on in May," Mr Quax said.
The latest admission, he said, showed just how dire the land supply was and an acknowledgement the council had got it seriously wrong.
"We need to be told the truth. I don't blame the mayor for this.
"I blame the officials for not doing a rigorous enough job of telling us what the supply of land is," Mr Quax said.
Building adjustment
Last month
Question to Mayor Len Brown: You say there is available land, infrastructure, roads, services all ready and 15,000 houses can be built on them straight away? Answer: "Right now."
Yesterday
"Around 2000 sections available now in greenfield areas. The remainder requires subdivision and internal servicing."