National leader Judith Collins says the latest lockdown will be difficult news for all New Zealanders.
In a statement she says: "I feel for the people who have already sacrificed their livelihoods, their jobs and their businesses to keep Covid-19 out."
But she urges everyone to follow the advice of health officials.
"The government must now move swiftly to find the source of this latest community outbreak, and to vaccinate our border workers as a matter of urgency.
"National has been calling for an accelerated rollout of vaccinations for border workers and frontline staff since January because we were acutely aware of the economic and social damage a third lockdown could cause.
"Avoiding this very scenario at all costs should have been the government's top priority.
"Whether or not this latest outbreak is traced back to the border does not matter. New Zealand cannot afford any more lockdowns. We should be taking every precaution.
"If this proves to be another border failure that is unacceptable. The government's shortcomings in the area have been shown up time and time again. The Roche/Simpson report was commissioned for this very reason. Our border should be rock-solid by now.
"The government was warned. They no longer have any excuses for failure."