Labour wants immigration checked at certain level but requires more detail.
Labour leader David Cunliffe wants to cut the level of immigration but won't say by how much. He said Labour did not have enough information to put a target on it.
"I think current levels are too high and they should be managed to a moderate sustainable level using the tools available to Government," he said.
"I'm not going to put a number on it because, quite simply, the Government has more detailed information than is available to the Opposition."
Prime Minister John Key challenged Mr Cunliffe to go to South Auckland and state the party's policy. He said Mr Cunliffe was "desperate" to run immigration because Labour's polling had the party consistently at 30 per cent.
Mr Cunliffe said immigration contributed to rising house prices with net migration at one of the highest levels it had been for many years.
"That will put pressure on interest rates. That will affect everybody's mortgages and it will make it more difficult for people to move into their own homes."
As well as reducing immigration Labour would increase housing supply, apply a capital gains tax to domestic investors and make it harder for overseas speculators to drive the property markets.
An usually high number of returning New Zealanders has boosted net migration, forecast to reach 40,000 this year - which hasn't been that high since 2003 when Mr Cunliffe was Minister of Immigration.
Mr Cunliffe recently extolled the virtues of the previous Government's target, saying it aimed to have net positive migration in a zone between 5000 and 15,000.
Housing spokesman Phil Twyford then repeated the zone of between 5000 and 15,000 as being Labour's target but Mr Cunliffe has since shifted away from it.
Mr Cunliffe did not believe the party would come up with a target before the election on September 20.
"It is possible to gradually and smoothly adjust the flows so helping to sustain our communities, add to economic growth but not put too much pressure on house prices."
Mr Key in Parliament yesterday pulled out former quotes of Mr Cunliffe's in support of immigration and accused him of "having a whack" at Labour's core constituency, migrants.
Earlier Mr Key said New Zealanders would take a step back and say the country was built on immigration.
"Everyone's a migrant pretty much of some sort.
"My mother was Austrian and my father was English. My wife's parents came from Ireland, so under David Cunliffe I wouldn't be here and Bronagh wouldn't be here."
He said New Zealand was actually very hard to get into and it needed skilled workers, such as oncologists and the specialist help from Japan needed to build the Waterview tunnel.
New Zealand was a young country, with 4.5 million people and a slowly rising population.
"But there will always be cycles and this is a cycle where we are more attractive than other destinations. The simple answer is that if New Zealand is a more attractive destination, then we should build a few more houses."