Labour leader Chris Hipkins is "quite unwell", a spokesperson says.
The incumbent Prime Minister tested positive for COVID-19 on Sunday, less than two weeks out from the October 14 election day and just a day before early voting opened.
A spokesperson on Monday morning said he was "still feeling quite unwell".
"He’s undertaking limited duties today, but aiming to pick up more things remotely from tomorrow, such as his morning media round."
Speaking at a policy announcement, Labour's commerce and consumer affairs spokesperson Dr Duncan Webb said Hipkins was "pretty rough".
"We probably won't be hearing from him today. But we are hopeful he will feel a bit better tomorrow and be able to hear from him then."
The Prime Minister's Office released a statement on Sunday saying Hipkins had cold and flu symptoms and would isolate for five days or until he returns a negative test.
"He will continue with engagements he can undertake via Zoom," the PM's office said.
However, a major event in the election calendar, the Press Leaders Debate, which was scheduled for Tuesday evening, has had to be postponed. Stuff, which is putting on the debate, said it was working to secure a new date for the face-off between Hipkins and National's Christopher Luxon.
Various Labour MPs will step in for Hipkins over the coming days.
Deputy Prime Minister Carmel Sepuloni held a standup on Sunday saying Hipkins was unwell on Saturday night.
She said she wasn't worried the loss of her party leader would be a handbrake on Labour's campaign.
"No, we can't let it," Sepuloni said. "Certainly the Prime Minister has been clear, he'll do as much as he can remotely on Zoom… I'm sure his brain will still be ticking over over the next few days and I can guarantee everyone will be getting instructions and phone calls. We just need to pick up where he's not able to."
