The Prime Minister won't be drawn on what impact planned changes to the country's immigration settings may have.

Changes to policy are to be unveiled by the Government this morning.

Mr English said they will be designed to get better control and better matching over the type of migrants the country is seeking.

"It's intended to control the flow and get the mix right," he said on Tuesday.

But Mr English won't speculate on how it might affect recent record inflows of migrants.

"The forecasts that have been made over the last couple of years have generally turned out to be wrong, that is, the attractiveness of New Zealand as a destination has meant that the numbers have held up I think longer than most of the forecasters expected, so that's a bit risky."

ANZ chief economist Cameron Bagrie told Nadine Higgins a broader look at those crying out for staff across the country, shows it's not just the construction industry.

"It's IT related, so the people we are bringing in might have admirable skills on the face of it, but if you look at where we've got real deficiencies, we've got a miss-match, so obviously we need a little bit of realignment here."

Association of Migration and Investment chairwoman June Ranson told Mike Hosking many migrants will welcome a change.

"They're in this country providing good skills, and they've had no pathway to get residence because of the great emphasis on qualifications."

Ranson said our Government needs to focus on getting skills where they're needed.

"We've got businesses that are downsizing and also some of them looking at closing, especially down in the South Island. New Zealand doesn't revolve around Auckland."

Record immigration rates have been in the news recently, and opposition parties say the huge number of newcomers is a major reason for Auckland's housing shortage.