Updated 2.49pm: Ngati Whatua is unhappy it hasn't had first dibs on the Government's latest plan to increase Auckland's housing stock.

The iwi says under its Treaty settlement with the Crown, it has the right to buy the vacant sites at market value before they're put on the market.

Building and Housing Minister Nick Smith said there's no specific right of first refusal in the settlement with Ngati Whatua, although there is one in the Tamaki Redress Act.

"But it specifically makes reference for the capacity of the government to develop and sell land for housing purposes."

But Ngati Whatua Orakei Trust spokesman Ngarimu Blair told Newstalk ZB's Mike Hosking it would use the land to build new homes.

"We're building more houses ourselves, we've got SHAs ourselves, so we totally understand what they're trying to do.

"We just want to be a part of it."

The iwi has called in the lawyers, saying the Government never talked to it about its intentions to sell several vacant sites to private developers.

Blair said that's a direct violation of their Treaty settlement with the Crown "in that we have a process which determines fair market value".

"If we don't agree with that value, we can walk away and then the government is able to sell it to whomever they like."

However, Prime Minister John Key stated Ngati Whatua hasn't got a leg to stand on.

"Not legally no, so if you basically use it for housing purposes as I understand, it doesn't trigger what's called the offer back provision and so no they aren't entitled."

Green Party Co-leader Metiria Turei is siding with the Iwi, saying the Government is finding tricky ways to evade its responsibilities.

"It is a legal entitlement that Ngati Whatua have, and no machinations by Nick Smith will relieve him of their obligation."