A church in south Auckland said if the homeless problem doesn't change then Otara could become a slum in five years.

Lupe Tukutau of the Free Wesleyan Church of Tonga joined Labour leader Andrew Little in south Auckland this afternoon to discuss the issue.

In an attempt to make a political point about the housing shortage, Little organised a press conference outside a house in Otara, where he believed overcrowding had forced some people to live in a tent.

But the home owner told waiting media to go away, and that they were only in the tent because of renovations.

Mr Little said Housing New Zealand's work has been unacceptable at getting people living out of garages and cars into homes.

Ms Tukutau agrees, saying something needs to be done quickly before the area turns into a slum.

"More people are building their own little tents or whatever because the population is increasing and the price of houses is going up of course, but renting is rising as well."

Mr Little said the problem is all over south Auckland as well as the rest of the country with some churches worrying about their members.

Ms Tukutau said in her church there are 30 different families who are living in garages or on the street.

"There is a lot. You don't have to look far.

"Some of the garages, they have curtains, there are families occupying the garage."

The Prime Minister said there's no reason why people should be living in cars.

John Key said he's been assured by welfare agencies that if people in these circumstances reach out - they'll be helped.

"If they ever get a case of someone who is living in a car, they will always take steps to help address that issue. That can be temporarily putting them in a hotel or finding a shelter for them. Ultimately working to long term solutions."

Mr Key said the Government would love the council to control the process and be able to deliver enough housing.

"But if they can't, the Government can't sit back and say it's solely an issue for Auckland councillors. We need to make sure there's enough land supply so that those houses can be built."