Handing state homes over to community providers may benefit corporate developers, the Green Party says.
Housing Minister Nick Smith has said he wants more social housing provided from within the community, rather than by the state.
Greens Housing spokeswoman Holly Walker said the community housing sector was an important part of solving the housing crisis.
But handing homes over to community organisations would risk benefiting corporate housing developers set up as pseudo-community providers.
"There is a real concern that if Nick Smith's plan is fast-tracked the beneficiaries will be National's developer mates, not the thousands of families in urgent need of affordable housing," Ms Walker said.