A midwife is expected to tell how she's had to deliver babies at night by the light of her cellphone at the cross-party inquiry into homelessness.

The inquiry, set up by Labour, the Greens and the Maori Pary, is in Tauranga on Monday. The Government blocked efforts to open an official investigation into the crisis, which is at record levels according to both research and social agencies like the Salvation Army.

"In her submission she talks about delivering babies by the light of her cellphone in squalid houses that don't have any electricity," Labour housing spokesperson Phil Twyford told Paul Henry.

Labour wants a state of emergency declared over the housing crisis, particularly in Auckland where prices are at record highs and still rising.

Prime Minister John Key says that won't happen, and the housing crisis - if it is one - is not his fault.

"Under the nine years that Helen was Prime Minister, my friend, nationally house prices went up 102 percent. Under us in eight years, they've gone up 43. In Auckland they went up 87 percent I think - under us it's about the same," he said.

"If it was a state of emergency now, a crisis now, why wasn't it a state of emergency and a crisis then?"

In a look at historic house prices earlier this year, the Reserve Bank called Auckland's latest boom "an unprecedented divergence". Though percentage increases year-on-year might have been lower during Mr Key's tenure, prices are increasing faster now because they're adding to a larger base cost than when Ms Clark took the reins in 1999.

"House prices in Auckland have doubled on his watch," says Mr Twyford.

"The average is now hitting $1 million. Home ownership rates are the lowest in 65 years and we have record homelessness. The Salvation Army says they haven't seen homelessness like this in living memory - but apparently, according to John Key, it's all Helen Clark's fault."

He wants the Government to triple the amount it's spending on emergency housing, stop selling state houses and build more, and make a call on how to house the homeless until those homes are ready.

"You could, if you chose to, if you had the political will, you could lease hundreds of houses and earmark them for supported emergency housing. Paula Bennett could do that today," he says.

"Paula Bennett's been dithering for months talking about pod housing, she's got a group of international consultants recommending warehouses, army barracks, someone's proposed tying up a cruise ship in the Port of Auckland. My message is I don't really care how you do it - just put a roof over the heads of these people. Make a decision, because that's why you're paid the big money."

Mr Key says Labour is "overstating" the crisis, and while he accepts prices are going up "too rapidly", at the same time interest rates are making inflated mortgages easier to service.

"If you have a $300,000 mortgage in Auckland, you compare it to when I first became Prime Minister, you're paying $16,000 a year less in interest."

Mr Twyford doubts Mr Key really cares what housing costs.

"If John Key stands for one thing, he likes to see people making lots of money buying and selling - when he sees an overheated Auckland property market with foreign investors and people shelling out millions of dollars for a home, he sees that as a sign of success. I don't."

Mr Twyford says he only owns one house, with his wife, so isn't adding to the problem by speculating on the market and blocking first-home buyers getting on the ladder.

Mr Key owns tens of millions of dollars' worth of property, including his family home in Parnell, two holiday homes, an office and an apartment in London.

A NZ Herald analysis of MPs' property portfolios found the top 10 owners, by value, were all National MPs.

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