Labour says it will take National's housing policy and put it on steroids - and announce details this weekend.
Leader Andrew Little says the new and improved housing package will be made public as part of Labour's centenary celebrations.
He says their housing package is in response to the Government's announcement on Sunday, which includes a $1 billion housing infrastructure fund to speed up new housing in the high-demand areas.
Little wouldn't give away much about the announcement to be made on Sunday, but said it'd be "comprehensive" and would include building "a lot of houses, over a period of time".
Labour already has a Kiwibuild policy but it is understood this will be an enhanced, "supersized" version.
He also didn't rule out removing negative gearing for investors.
"I'm not going to get into a lot of detail, but we're taking the issue seriously."
"For the last few weeks [the Government] have made several efforts to give the appearance of doing something and what they've turned up is a hodgepodge of ideas, fiddled and faddled around and done nothing meaningful.
"They did nothing in the Budget, they had an attempt on the eve of the Budget to scramble together Paula Bennett's policy that no one else knew anything about and this weekend they've announced something that simply will not fix the problems that we've got."
John Key says the Government is aiming to "get on top of the supply side" so land-banking becomes far less profitable.
"We're not looking to actively declare war on people who are private property owners."
Whether land-banking is wrong depends on where and why people are doing it, he says.
"Some people might buy land a long way out of the city because they know one day the city will come to them.
"You can't pass a law saying there can't be land-bankers."