UPDATED 4.43pm ACT Party leader David Seymour has roundly criticised the National Party during his 'State of the Nation' address in Auckland this afternoon.

LISTEN ABOVE: David Seymour speaks to Larry Williams

Mr Seymour, who is the party's only MP, pointed out that the government has failed to fix the housing affordability issue, stating that it had actively avoided the issue.

It was revealed today that Auckland has gone from the world's fifth least affordable city to its fourth, now tailing only Hong Kong, Sydney and Vancouver as the least accessible housing market.

Auckland's median house price is $830,000 yet residents' median household income is $83,000 giving a multiple of 10, up on last year's 9.7 when house prices were only $748,700 and incomes were $77,500, according to figures from Demographia.

Given the average National MP owns 2.3 houses, Mr Seymour stated, it's possible they just don't care about housing affordability.

He says something's gone seriously wrong.

"It's difficult to escape the suspicion that actually you've got a party the full of people. The average National MP owning 2.3 houses of their own who actually didn't want to implement policies that would work. I think that's a terrible shame," Mr Seymour told Larry Williams.

He also said their lack of ambition is not surprising, given their belief that rising prices would keep the economy buoyant, and therefore would keep them popular.

"Because people feel good and feel wealthy when values go up. The only difficulty that they haven't foreseen is that now even the people who have benefited are starting to say 'woah this is getting crazy and why haven't you done something about it.'"

Mr Seymour said it will go down as one of the most cynical pieces of politics in New Zealand's history.

"They're now in big political trouble because they can't credibly say they're going to fix something that they've been denying was a problem for a long period of time, when the majority of even their  supporters think it is a problem."

Mr Seymour said the Government will only be able to successfully address housing affordability with ACT's help.

"We're going to actually accept that there's a problem. We're going take serious action including new legislation on urban planning, new funding for infrastructure, and new ways of consenting builds so that there will actually be a supply of housing in New Zealand."

The official waiting list for social housing rose to nearly 4800 households at the end of last year, according to government figures. 

The National-led Government began funding emergency housing for the first time in late 2015 following a review of the sector.

"As a nation we are aware that the demand for housing is putting pressure on families, particularly in Auckland," social housing minister Amy Adams said last week.

"We've been actively encouraging people to get in touch with Work and Income when they need help and I'm pleased to see that message getting through."