Record net migration to New Zealand is a reflection of Australia's weakening economy, Labour Party leader Andrew Little says.
Official figures show immigration hit a record high of 117,866 people in the year to August, driven by New Zealanders returning from Australia and Indians arriving on student visas.
The net gain to New Zealand - accounting for the numbers that left during the year - was more than 60,000 people, the 13th successive month of record highs.
Just 529 people left for Australia during the year, the smallest annual loss since 1991.
Prime Minister John Key said he thought immigration numbers were about right, and it was a vote of confidence in New Zealand.
But Mr Little said the numbers were more about the slowdown in Australia.
"The opportunities in Australia are much fewer. We've had not too bad a time here more recently but actually things are slowing down here quite dramatically," he said.
"So I guess you've got to look at next year's figures or figures in a couple of years' time to see whether people are continuing to vote the same way."
Mr Little said New Zealand still had a skill gap, and employers hiring people from overseas needed to be filling that gap.
Meanwhile, New Zealanders took a record number of overseas trips in the year to August, up 6 percent to 2.36 million, with half of them to Australia.