New Zealand First's proposed immigration 'reset' is raising questions.

It's launched its election campaign, with leader Winston Peters saying the party would cap immigration at 15,000 people per year- and those places would only go to highly-skilled workers.

Immigration advisor Simon Moore told Kate Hawkesby the economy needs overseas workers to function.

"The thing is that you can't just magic people up.

"We've still got over 200,000 people on work visas, which goes to show that we don't have the people here."

He says this cap will severely affect industries that have failed to attract Kiwi workers.  

"Aged care workers did quite a significant pay increase, but it didn't attract New Zealanders into that sector."