New Zealand's net migration rate is unsustainable - and the government needs to consider the effects on infrastructure, Immigration expert Paul Spoonley says.
But there's little difference between the approaches put forward by the different political parties, he says, and it's unclear what the government is planning to do about it.
Prime Minister Christopher Luxon on Monday told Morning Report he believed immigration levels were unsustainable, putting the blame on the previous government.
"We're inheriting a system that's been a complete hash," he said.
Labour agreed the settings may need to be tightened but rejected criticism of its record, with spokesperson Phil Twyford saying Luxon's comments were surprising given he had been "incessantly calling on Labour to loosen the rules, to bring more people in".
"For the last few years the only thing we heard from National really was berating the former Labour government for first having closed the border to protect the country during Covid and then in the immediate post-Covid period just constantly saying loosen the restrictions, let more people in - it was a never-ending chorus."
All this followed news Australia's Labor-led government - which was making similar accusatory noises about its predecessor - would be introducing a series of changes to its own immigration system. This would include replacing its skills shortage visa, imposing stricter language requirements for international students, and increasing scrutiny on people applying for secondary visas.
Prof Spoonley told RNZ the roughly 118,800 net increase in the year to September was easily the highest level New Zealand had ever experienced.
"At the beginning of this year a lot of commentators were really questioning whether New Zealand would ever see immigrants coming here again. And we've seen quite the reverse, I mean the numbers are quite extraordinary ... certainly we've gone from that Covid bust to a current immigration boom," he said.
"At 118,000 it looks as though this year New Zealand's population will grow at around 2.5 percent. What that means is that there are demand for all sorts of services and of course, infrastructure and we're already struggling to try and match infrastructure to our existing population.
"So when you get rapid population growth - in this case, driven by immigration - of course, it all adds to that stress adds to that.
There were concerns about the Accredited Employer Work Visa scheme Labour brought in, with processing and approval problems and tighter management of how immigrants were treated when they arrived, he said.
Business New Zealand advocacy director Catherine Beard cautioned, however, that the high figures could be a post-pandemic blip that may yet drop down again.
"Some of those high numbers are actually family reunification as well, so families of people with visas. So it could actually come back down," she said.
"So we probably just need to watch the data a wee bit, but we're all for having a plan."
Twyford told Morning Report New Zealand experienced an acute skills shortage after the pandemic.
For a long time National had been the party of immigration, particularly low skill and low wage immigration, he said.
"Now if Mr Luxon's had a change of heart and actually wants a more targeted immigration scheme, to much more carefully meet particular skills shortages and not flood the market with low wage temporary migrant labour, I'll be the first to congratulate him."
Former boss of Business NZ, Iron Duke Partners managing director Phil O'Reilly, said a strategy was needed.
"The key is to make sure the system is nimble, taking account of labour market needs, that it doesn't just have high skilled migrants in it, that it also has migrants potenially who are lower skilled," he told Morning Report.
"We need people to pour beer for our Christmas party in Queenstown - they're not going to be high skilled."
Talking to the business community about what they logically needed was important, he said.
While New Zealand could live with high immigration numbers for a year or two, if this continued there would be some stress on infrastructre and a lot of people arriving who do not have the right skills, he said.
But migrants do help build this infrastructure, he said.
A balance was needed between making sure employers had the rights skills and making sure they were also investing in skills training, upgrading current equipment and investing in capital equipment, he said.
"That's why you need a strategy, this just endless politicking around opening the gates and closing them just gets us nowhere."
Fresh figures due out on Tuesday should make clear whether the trend is coming down. If not, the question remains what more could be done. Prof Spoonley said he could see few major issues - and little in the way of major differences between the various political parties in Parliament.
"I've had a good look at the coalition agreements and the policies of the key parties coming into the election. I don't see major differences between, let's say Labour and the Greens and National, ACT and even New Zealand First, but it's certainly true that we need to have a good look at some of those policy settings.
"The other thing is, of course, the number. If the current number of 118,000 is too high what is the what is the more appropriate number? What does that look like? And I listened very carefully to Christopher Luxon's comments and I'm just not sure what they've got in mind."
He said New Zealand's demographics were changing - affected also by things like falling fertility and an ageing population - but the country had never really had a national discussion about how immigration should fit into that.
He hoped the new minister, Erica Stanford, would consult widely and make good use of the information that was already available - pointing to a Productivity Commission report from May 2022 which he said laid out the policy problems and tension points clearly.