The Prime Minister maintains it's not entirely unusual for the head of a major bank to wade in on economic issues.

LISTEN ABOVE: Rachel Smalley speaks to John Key about the housing crisis

ANZ chief executive David Hisco has turned heads by suggesting a number of measures be urgently adopted to stop what he says will be a "messy end" to the housing boom.

He wants LVRs increased above the Reserve Bank's 40% investor deposits, and banks to voluntarily tighten their own lending criteria.

Mr Hisco also wants action taken to weaken the New Zealand dollar, and the Government to review its immigration policies.

Prime Minister John Key told Rachel Smalley banks make statements through their economists all the time.

"He's quite entitled to make his views, we may agree with some and may not agree with others."

Labour MP Grant Robertson sees it as significant that the chief executive of one of our largest banks is saying not enough is being done to fix the housing crisis.

"They will be looking at it from their perspective, the banks are wanting stability in the system."

"Their exposure is high, whichever way things go with the housing crisis, and so they are speaking out, no doubt from their own interest but also because they can see what's coming."