Auckland Mayor Phil Goff says if the city was to go back into alert level 4 it would need government assistance.
The country will be told this evening if the Covid-19 lockdown measures will be extended past midnight. Auckland has been at alert level 3 restrictions since Wednesday; the rest of the country is at level 2.
Goff said the council had had a half-a-billion dollar loss in income from the last lockdown, and can't borrow more.
He told Finance Minister Grant Robertson "the petrol tank is empty".
The mayor said he was looking forward to hearing Robertson's plan for further economic support if the heightened alert level was in place for an extended period or raised to level 4.
If Auckland was to go into level 4, half the workforce would be home and not working "and that would be a serious situation".
It was important to continue keeping spending up on infrastructure, and Auckland would need greater assistance from the government to keep those jobs going, he said.
"So that we can continue doing that work of building infrastructure, regenerating the economy, creating jobs ... greater assistance by government to ensure we can fund those infrastructure jobs would be hugely important."
Goff said he had written to ministers, including the health minister, saying it was almost inevitable we would get further outbreaks, to make sure council and government planning was lined up.
"I don't think our response to Covid-19 has been perfect, I think it's been good, I think it's been world-leading - we've been incredibly fortunate with good management and good leadership.
"But it is such rampant virus internationally and with the people returning home to New Zealand we had to be ready for this and I think by and large we have been."
Regular border worker testing 'important'
Goff said he had not be aware of the level of non-testing of border workers, as reported by Newshub which said around 60 percent had not been tested as of 3 August.
"I assumed the testing would be regular there.
"I think it's really important that we close that off and make sure that there is regular testing there."
"My understanding is there may be some legal constraint but we've got to work around that.
"It's just a matter of common sense that those working in quarantine and those working at the border are regularly tested and that needs to happen.
He was pleased that 7800 tests had been carried out in Auckland on Wednesday and that needed to continue.
In his letter to the health minister he raised the question of to whether people are put off being tested because of the nasal swab, which can look intrusive, and was told the test was the most consistently reliable one available.
People had become complacent and people with symptoms weren't getting tested as much as they should.
"I think the complacency was shared by all of us... I'm not just going to point the finger just at government. This is a team game we're all in this together and we've all got a role to play"
He said New Zealand did better than almost any other country and will beat the outbreak again.
"Go hard and go early worked well for us last time ... and it will work for us again."
Goff said there was no guarantee there weren't other clusters. "So let's get on top of the spread of Covid and then get on top of economic recovery."
Level 3 business rules 'selecting winners and losers'
The Auckland Business Chamber says all of its members should be allowed to open as long as they comply with strict social distancing rules.
Chief executive Michael Barnett told Morning Report the present rules are confusing and by saying which stores can stay open are "selecting winners and losers".
Under level 3 restrictions hospitality and retail businesses can trade only online, or provide takeaways.
Supermarkets, dairies, petrol stations and pharmacies can have customers on their premises.
Barnett said he would would prefer a set of rules that all businesses had to follow.
"If you have a set of rules ... then you can determine who can best stay open rather than the government determining those that are winners and those that are losers.
"Quite frankly businesses trusted government and somebody's taken their eye off the ball and to go into lockdown is a cost that's way too high both for employers and employees."
People making the decisions have salary certainty but business owners and employers don't, he said.
"I believe with clear and consistent rules we're going to get a much fairer result."