More people think National's controversial plan to make low-paid foreign workers leave the country after three years of work is fair than unfair, but not by much - 48 per cent to 41 per cent, in a Herald-ZB-Kantar TNS poll.

The Government announced the policy last month after putting it out for consultation in April, but many employers cried foul.

From August 28, migrants earning less than $41,538 a year will be considered a lower-skilled worker and will have to leave New Zealand for at least a year before reapplying for a work visa. Respondents were given these options:

• It is unfair on employers who can't get New Zealanders for their jobs and who will train foreign staff only to see them leave; which got 41 per cent.

• It is fair and will give employers an incentive to hire and train unemployed New Zealanders; which got 48 per cent.

Only 11 per cent were not sure.

The most pronounced support for the limits on low-skilled migrants was from people from Auckland - 57 per cent believe it is fair while only 36 per cent think it is unfair. In Wellington the policy was supported by 48 per cent of people, and opposed by 38 per cent.

The most pronounced opposition to the policy was from people in Canterbury, where many foreigners have helped with the earthquake rebuild: 50 per cent thought it was unfair and 42 per cent thought it was fair.

More males than females thought it was fair, 50 per cent to 46 per cent.

And more young people support it, 52 per cent aged 18 to 19, while only 45 per cent aged 60 and over thought it was fair.

It was part of a move to determine skill levels by remuneration bands. Anyone earning over $73,299 will be considered high skilled, no matter what their occupation.

Immigration Minister Michael Woodhouse said at the time it was a balanced and pragmatic approach.