New Zealander First Leader Winston Peters gave a scathing review of National's proposed offshore testing scheme, which would require returnees to get a negative COVID test before being allowed to head to New Zealand.
Speaking to Magic Talk host Peter Williams on Tuesday, Mr Peters says the plan "defies all medical analysis".
"It's a worthwhile policy unless you rely upon it because being tested before you get on the plane showing no symptoms does not mean you're COVID free," he says.
"That's the great flaw in their argument and I'm surprised that with Dr Reti on board now after all this time that they have missed the dangers of relying upon testing offshore, the person yet to show symptoms or picking up symptoms on the way through in the long transit.
"Yes it's a protection and we could enforce that as well but to think that someone is therefore COVID-free defies all medical analysis."
Mr Peters says there are a limited number of places in the world where Kiwis can be assured of getting the required testing done.
"If you're in South Africa or the Middle East how are you going to get home?" he asks.
"Already they've put an enormous impediment on people because they can't get to the agency and yet I heard the National Party say 'well they'll just have to fix themselves up before they get back to this country'.
"That means it'll be absolutely impossible. They could be COVID-free, they can't get a test because of the nature of the country where they are."