Green Party co-Leader Metiria Turei is defending Housing New Zealand (HNZ) after Newshub revealed thousands of three-bedroom state homes are being occupied by a single person.
Ms Turei says HNZ isn't a good landlord because it's the victim of National's policies.
"National has prevented Housing New Zealand from being a proper landlord. They've taken away their ability to respond to families' needs and they're not giving them the opportunity to build the housing New Zealanders need."
HNZ figures showed that as of February this year, 2320 three-bedroom state houses are occupied by one person each, meaning more than 4500 bedrooms are empty.
Social Housing Minister Paula Bennett puts this down to decades of "poor asset management" by HNZ.
Ms Turei believes many of the tenants in the apparently under-occupied properties have family staying with them, but can't tell HNZ because they're too scared they'll be kicked out.
"The raw numbers actually don't tell the whole story."
Ms Bennett says tenancy reviews were introduced in July 2014 to address current issues.
Ministry of Social Development staff have begun 4955 reviews of social housing tenancies.
"As a result, 572 households have moved into private rentals, 92 have bought their own homes and 117 have moved out for other reasons," Ms Bennett said.