Election 2020: New poll tonight, Jacinda Ardern and Judith Collins in first TVNZ debate

Prime Minister Jacinda Ardern and Opposition leader Judith Collins prepare to face off in tonight's first live televised leaders' debate. Photo / Getty Images, File

The much-awaited first leaders debate between the Prime Minister and leader of the Opposition will take place tonight in a week of political missteps from both women.

This will be the first time Jacinda Ardern and Judith Collins have clashed head-to-head in a studio in the lead up to October's general election.

The pair will face off at 7pm on TVNZ 1.

The showdown will be the first of three on-air debates featuring Ardern and Collins before October 17.

They will have a rematch on Three next week and again just two days before the election returning to TVNZ.

While Labour's popularity has soared to unparalleled levels in recent times - and a new TVNZ-Colmar Brunton poll due out just an hour before the televised clash takes place - it comes as both leaders are forced to acknowledge errors in recent days.

Ardern yesterday apologised for participating in selfies that broke her own social distancing rules, admitting she "made a mistake".

The Prime Minister was photographed taking a selfie with tradies on the campaign trail in Palmerston North without appropriate social distancing or the wearing of face masks.

"In that particular photo I made a mistake," Ardern later said.

"I should have moved further forwards and I should have asked them to step apart as well."

And just hours before Collins launched her party's election campaign, her finance spokesman was forced to admit there was a $4 billion error in their alternative budget calculations.

"We make mistakes from time to time," Paul Goldsmith said, adding: "I never claimed to be perfect."

Hours out from the hotly anticipated clash, Ardern says her approach will remain focused on sharing the party's vision.

"I spend a little less time thinking about sparring with the person opposite and more about directly communicating what our plans are."

As for Collins, after two months at the helm and her party languishing on 32 per cent in the last Colmar Brunton poll, the National leader plans on taking a different approach.

"I'm not playing to lose," she said.