Labour's Andrew Little is accusing National of "conspiracy theory muckraking" over Auckland's COVID-19 outbreak.
It comes as the Opposition criticises the Government after Newshub's Michael Morrah last week revealed more than 60 percent of all border and hotel isolation workers in the city had never been tested, despite assurances this was happening.
It's now mandatory for those working at the border to be tested.
National deputy leader Gerry Brownlee, in Parliament on Wednesday, slammed the Government's coronavirus resurgence plan saying it "let COVID-19 through the border".
But in response, Justice Minister Little said Brownlee's comments "epitomises the state of the National Party Opposition".
"There is one place where you can get accurate information, and that is from those sources and from Government sources. Not the kind of conspiracy theory muckraking that we've seen from the Opposition - none of that sort of nonsense," Little told MPs.
"At a time when communities and families are feeling fragile and are needing reassurance, going down that path is simply not helping and, in fact, it's the opposite - it is quite destructive.
"Like everything this Government does, it is about the wellbeing of New Zealand - the wellbeing of New Zealanders collectively doing the right response and making sure people are looked after, and taken care of."
Brownlee said the original case from Auckland's COVID-19 cluster "appeared from nowhere", with officials yet to determine its source. He said, "that should worry every New Zealander".
"If there was any optimism shown by this side of the House about what New Zealand might be able to do as we progressed from the last bout of COVID-19 in this country, it's because the Government was relentlessly optimistic about the situation and therefore every New Zealander was optimistic about the current situation," Brownlee said.
National leader Judith Collins said COVID-19 re-emerging was "this mess that we've been given as the people of New Zealand".
"It's five months since New Zealand went into lockdown the first time, and in five months New Zealanders would have expected that we would have a Government putting all its efforts into making sure that this virus did not resurge back into the community."
Health Minister Chris Hipkins launched back at Collins.
"We've been telling New Zealanders of the need to remain vigilant, we have been putting in place plans to ensure that if we were confronted with COVID-19 again, we could rise to the occasion, as we did the first time around," he said.
"What did we get from the Opposition with regard to those plans? We got accused of scaremongering; all sorts of conspiracy theories about, 'what did we know that they didn't know?', when we were telling New Zealanders that they simply needed to be prepared."
Little said New Zealanders had risen to the challenge of fighting COVID-19.
"This Government has provided a rapid, focused, a science, and evidence-based, and a resolute response to the arrival of that vicious little virus in our beautiful little country, and we have been more successful than just about every other country in the world."
