The Labour Party is calling for a state of emergency to be declared on homelessness.
The party's housing spokesperson Phil Twyford said homelessness had reached an unprecendented crisis point and decisive intervention was needed.
Mr Twyford said just as in a natural disaster, declaring a state of emergency would galvanise resources and the political will to fix the problem.
The latest figues from an independent Otago study into homelessness show 41,000 people have no home and are living in cars, garages, caravan parks and on the street.
Mr Twyford said the government must take urgent action by tripling spending on emergency housing overnight, building more homes and stopping the sale of state houses.
He said the government was dithering over housing when action was needed.
"I don't really care how the government does it, that's what they're paid the big money for is to make decisions, so they just need to make a decision, put a roof over the heads of homeless people and do it now."