National says if it's good enough to wait until April to let in international tourists, it's "good enough now".
But Labour says New Zealand "can't just throw open the doors" as some tourism operators are demanding.
On Thursday, COVID-19 Response Minister Chris Hipkins revealed that from April 30, fully vaccinated foreigners will be allowed into the country - but they must self-isolate for seven days before seeing the sights.
"I can assure you, as a tourism business, not a single international customer will want to self isolate in any shape or form," Wendy Van Lieshout, chief executive of Active Adventures, told Newshub.
The Tourism Export Council said the self-isolation requirement was "total nonsense" and our international reputation will be "smashed to smithereens" if we don't open up "within the next week or two", ahead of summer.
"It's control freakery by the Government," National MP Simon Bridges told The AM Show on Friday.
"It's good at a level that there's certainty we know things will open up, but actually if it's good enough then, it's good enough now. The risks are minimal from letting in Aussies and so on who have been double-vaccinated and had pre-departure tests.
"As [Prime Minister] Jacinda [Ardern] once said, let's do this."
Labour MP David Parker, appearing with Bridges, acknowledged the date wasn't as soon as the tourism industry might like.
"I think we've got to remember Delta only arrived in August, and it's now November, and in that period in terms of our internal settings, we've completely changed things around very carefully.
"If we were just to throw open the doors and have unrestricted tourism with no self-isolation, the estimates are that we would be seeding an additional 60 cases or so into the community every week. Those 60 cases wouldn't be linked to earlier cases, and would be causing an increase in the spread of COVID. We're not willing to do that."
Vaccination means the border restrictions can be loosened, he said - for example, by letting in fully vaccinated Kiwis arriving from Australia from January 17, isolating at home for a week rather than having to cross their fingers for a pricy spot in managed isolation and quarantine (MIQ).
"But you can't just throw open the doors," Parker added. "We've led the world and still are, with the lowest death rate, the lowest hospitalisation rate and the lowest infection rate in the OECD, and we're not willing to throw that away."
Despite the tourism industry's struggles the New Zealand economy has fared better than most of its international peers, analysts crediting the low - and for a time, zero - rate of local cases of COVID-19.