ACT leader David Seymour says the Government has an "attitude problem" - and its "complacency' dealing with COVID-19 has led to the latest lockdown.

Prime Minister Jacinda Ardern announced on Saturday night that following a new community case Auckland would return to alert level 3 and the rest of New Zealand to alert level 2 for a week, starting 6am Sunday.

But Seymour says this was both foreseeable and avoidable if the Government had followed his advice from the start.

"Unfortunately ACT predicted tonight's plunge back into level 3 lockdown for Auckland and the rest of New Zealand into level 2," he says in a statement.

"I said yesterday the south Auckland cluster wasn't under control. It wasn't. There have been too many cases popping up randomly for the Government to be as confident as it was. We were a sitting duck, praying for luck."

• One year since New Zealand recorded first case of coronavirus
• Auckland to move to alert level 3, New Zealand to level 2, Jacinda Ardern announces
• One new community case, sibling of casual-plus contact
• One new COVID-19 cases in MIQ reported on Saturday, zero in community

Seymour says the Government has been "busy congratulating itself" and it has an "attitude problem".

"There has been no significant improvement to our defences since the second lockdown, but the impact of this fourth lockdown will be so much worse," he says

"Despite the many support packages in place the disruption of lockdown cripples businesses. Cafes that just got going after the third lockdown will have to dump several days stock, because they got only nine hours' notice of the fourth. It didn't need to be this way."

Seymour has been calling for a "complete reset" of our approach to tackling coronavirus, including:

• the mandatory use of the official COVID Tracer app
• daily saliva tests for border and MIQ staff
• earlier access to vaccines
• a multi-disciplinary, public and private sector Epidemic Response Unit

"These things weren't only within the Government's ability to implement, they were recommended by the Simpson Roche Report. The Government has failed because it had an attitude problem," he says.

"The Government must stop being complacent, and get started on continuous improvement. 

"Ignoring that advice has got us where we are tonight, yo-yo-ing in and out of lockdown - the very thing the Prime Minister promised we would avoid on her watch."