National leader Christopher Luxon accepts that "we need to get through the peak" of Omicron before welcoming tourists back to New Zealand.
Luxon made the comments on Wednesday speaking to AM's Ryan Bridge, who asked the Opposition leader if he could see why it would be difficult for the Government to put a firm date on when tourists should return.
"The bottom line is, we do need to get through the peak," Luxon, the former chief executive of Air New Zealand, told AM.
"Getting Kiwis here isolation-free with a negative test I think was a really good move, we've been calling for it for a very long period of time, that's a good start.
"But I think tourists, we need to get on the other side of the peak and then get going."
The Government announced on Monday that vaccinated Kiwis overseas could return to New Zealand without having to self-isolate for seven days from this Friday. But the Government is yet to confirm if it will bring forward the July date set for when tourists can enter.
"Our point would be straight after the peak of Omicron. That's going to be in the next three to six weeks, I imagine, and we should be gearing up to get tourists back in very quickly," Luxon told AM.
"The reality is that tourists aren't coming for a long period of time and I can tell you airline capacity isn't going to come if we don't have tourism demand. We've got to get through the peak, but once we've come through that, we should be straight into it."
Luxon's comments were in contrast to ACT leader David Seymour, who in Parliament on Tuesday demanded evidence from Prime Minister Jacinda Ardern that not allowing tourists in right now outweighed the benefits of welcoming them in.
Ardern responded: "With 10,000 arrivals in New Zealand, we have an estimate of between 100 and 485 cases coming in at the border. However, that is modelled with seven days of self-isolation, so you would expect a higher rate of cases if you were not to have self-isolation.
"You would expect even further cases if you have not just 10,000 entries but tens of thousands of entries. We have asked our experts to consider what the likely impact would be of bringing forward tourism and a wider reopening."
Seymour said there was "no reason not to let all travellers come to New Zealand and self isolate" because "a few hundred extra cases a day in the context of 20,000 domestic cases per day is irrelevant".
But Ardern issued caution, pointing to advice prepared for the Government by the Strategic COVID-19 Public Health Advisory Group led by Sir David Skegg.
The advice said: "In November 2021, there were concerted calls to drop all quarantine requirements for most vaccinated people arriving in Auckland, on the grounds that such travellers were less likely to be infected than Auckland residents at this time. This would have led to a major increase in Delta cases.
"Fortunately, the Government did not yield to the pressure, so our Delta outbreak was brought under control before the arrival of Omicron. In Australia, hospitals were still struggling to deal with the very large number of sick patients infected with the Delta variant when the Omicron outbreak took off."
The advice said while Omicron "did eventually creep into the community, we have had two or three important extra months to prepare for our Omicron wave" by administering booster vaccinations, which 70 percent of the eligible population has taken up.
Border cases have been decreasing over the past month, however, both in number and as a proportion of arriving travellers. The seven-day average for border cases at the weekend was 9.4, compared with a seven-day average of around 6700 for cases in the community.
"What we need is cost benefit analysis," Seymour said.
"What are the benefits of opening the border to foreigners without isolation requirements, and what are the costs to cases and hospitalisation? Without knowing that, Jacinda is playing politics with people's lives."
COVID-19 Response Minister Chris Hipkins said on Monday "caution has served us well" throughout the pandemic.
"As we continue to move through the Omicron outbreak and peak, we will continue to remove restrictions when advised it is safe to do so - as we always said we would."
But that's not good enough for Seymour.
"We should not keep ineffective and costly rules because they make us feel comfortable if there's no evidence that they work. If rules are not useful they should go, and it should be up to the Government that imposes them on us to explain why they should stay. It's time to stop the fear and the control. It's time to move on."