The Minister of Health has categorically ruled out Auckland staying at alert level 3.
Chris Hipkins says the move to alert level 2 will be more like level 2.5, with masks being mandatory on public transport and a limit on social gathering numbers.
Hipkins told Magic Talk's Road to the Election that authorities are weighing up all of the risks.
"We're still ploughing ahead with level 2 today. The key thing for us is looking at that cluster - are all the cases within the cluster, are they known and identified? The evidence so far is yes, they are."
Sunday's COVID-19 cases will be released in a press conference at 1pm with Prime Minister Jacinda Ardern. Hipkins says there are "slightly" fewer to report than Saturday's numbers, when 11 cases in the community were recorded.
Asked by host Mitch McCann how many cases a day it would take to trigger a return to level 3, he said it would depend on "the nature of the cases".
"This is one cluster with a bit of a strong sub-cluster building around it... they're all people, by and large, who we've known about and [have] been in isolation."
A "trigger" would be a number of cases cropping up that health officials "can't explain", he said.
The source of the outbreak remains a mystery. Suspects include the port, a leak from managed isolation and quarantine facilities, a cool-store and undetected transmission since the return to level 1 in May.
Hipkins said most leads have been dead-ends.
"Every new piece of the puzzle helps to paint a bit more of a picture of where it might have come from."
Phylogeneticist James Hadfield told RNZ on Saturday it's unlikely that the virus has been spreading undetected through the community since the first lockdown, as it would have had to go through at least 15 people without being picked up.
"Given they're all low probability events and we have seen a reemergence in Auckland, it's probable one of them is true, but it would be a brave person to put your money on any particular one," he said of the different theories.
Hipkins also had a message for people out and about at parks, beaches and protests this weekend.
"It's getting close to spring - I think people are eager to be out and about. My message to those people eager to be out and about is if you follow the rules now, then restrictions won't last as long."
This lockdown has seen a "little bit more rule breaking" than the first, Hipkins said - but overall, most Kiwis had played their part well.
"I still think overall Aucklanders' efforts have been pretty good here."