The Labour Party is having to find new options on the campaign trail now that its leader Chris Hipkins is isolating with Covid-19.

Senior MPs Carmel Sepuloni and Duncan Webb will take Hipkins' place at campaign events on Monday, while he will participate in other events via Zoom.

With Tuesday's The Press Leaders' Debate at risk, rather than try to reschedule, National's Chris Bishop has instead suggested Labour deputy Kelvin Davis and his own party's Nicola Willis go head-to-head instead.

Labour campaign chair Megan Woods says they were trying to "wrangle" a new date, but it wasn't going to be easy, with Hipkins likely out of in-person action until at least Friday.

"To quote Chris, 'Bugger'. Clearly this isn't something we ever wanted to happen. But as I said, this is not the first time people have had to rearrange things because of Covid."

Early voting is starting on Monday, with the opening of the first polling booths from 9am.

About 400 voting places will open around the country, and that number will gradually increase to 2300 sites on election day.

- RNZ.