He told the Q&A programme that the target for the Government was to get house prices to about four times incomes.

“Currently in Auckland it's seven. I've set that long-term objective of getting it back to four. That means incomes are growing faster than house prices and you need that repeatedly over a period of a decade or two to get those ratios down,” he said.

“If you look at housing ownership in New Zealand, it's been going backwards every single year since 1987...And if you're looking for some instant magic bullet that the government can wave and change those 20-year trends you're mistaken.”

Smith said a capital gains tax would not make any difference to the housing market.

“Look across the Tasman to Australia. They’ve got restrictions on farm buyers. They’ve got a sort of a capital gains tax of sorts and their house prices have gone up by more than New Zealand in the last 12 months.

“The government's measures that we're taking in those five key areas identified by the Productivity Commission, land supply, materials costs, Council infrastructure costs, productivity and compliance costs – they are the bits. If you are serious about not playing political games, but making changes that will make housing more affordable for our kids and their kids, they are the five things to tackle.”