NZ Election 2020: Five things to know before the Judith Collins vs Jacinda Ardern debate

National leader Judith Collins and Labour leader Jacinda Ardern are going head-to-head in their first television debate of the 2020 election.

This live showdown sees the potential leaders of New Zealand battle for your vote. Here are five things you need to know before it begins.

Where and when can you follow the debate?

The debate will be held at 7pm on Tuesday. You can follow Newshub's live updates here.

Who's hosting it?

The debate will be moderated by veteran broadcaster John Campbell. The last time Campbell hosted a major televised election debate was in 2014, when former Prime Minister John Key took on then-Labour leader David Cunliffe in the TV3 leader's debate.

How will the new poll impact it?

The debate will be held just after the latest 1 NEWS-Colmar Brunton political poll results were released.

This has Labour on 48 percent, National on 31 percent, ACT on 7 percent, the Greens on 6 percent and New Zealand First on 2 percent. As preferred Prime Minister, Ardern was unchanged on 54 percent, while Collins dropped 2 percent to 18 percent.

The last Newshub-Reid Research Poll in July - the first under Collins' leadership - had National down to 25.1 percent. Labour was up on 60.9 percent. Ardern was on 62 percent as preferred Prime Minister, ahead of Collins on 14.6 percent.

The 1 NEWS-Colmar Brunton poll will add to the pressure for Collins who faces an uphill climb into power. And while the poll shows Labour could govern alone with 62 seats, it dropped 5 percent in support and loses New Zealand First as a possible coalition partner. 

What will the main issues be?

For National these include the Ardern Government's track record on KiwiBuild, child poverty reduction, and transport

Ardern says she expects Collins to bring up KiwiBuild failures during the debate, "because if that's her one attack, I'm happy to take it, because I'm proud of our record". 

She's also defending her record on child poverty and homelessness.

"Seven out of the nine child poverty indicators have improved under this Government and that's only been in the short time that we've been in. Am I finished? Absolutely not," she said.

"The last time I was at the Auckland City Mission I had multiple family members tell me they were in a new-build because of the work we'd done, and they were warm and dry now."

Perennial debate issues include soaring house prices, climate change,  and tax plans. Following the announcement New Zealand is in a recession, expect strong debate on rising unemployment and how to bring us back into economic growth.

Collins could face tough questions of her own after it was revealed National had used the wrong numbers in calculating how much it would save from halting NZ Super Fund contributions, which resulted in a $4 billion fiscal hole. It also miscounted its capital allowance - the money put aside to build things like schools and hospitals - leaving National with another shortfall of $88 million.

National's proposed border security plan - which would allow private accommodation to provide managed isolation facilities - could also be an area of weakness.

What are each leaders' strategies to win?

With National the underdog this election, Collins needs a win. She's planning on getting this by reminding the Prime Minister of "what she hasn't done".

"She made some big promises and most of them she hasn't kept so I'll be reminding her of what she hasn't done," she told Magic Talk's Ryan Bridge ahead of the Tuesday night debate.

Expect some trademark sharp barbs to try and rattle Ardern - Collins doesn't have much to lose by going hard.

"While she has a different, more pugnacious style, Collins is also highly articulate, forceful in her speech and quick on her feet. The debate is her first real campaign opportunity to demonstrate those points of difference," Massey University Professor Ted Zorn wrote for The Conversation.

Ardern is expected to focus on the trust the public has in the Government has to combat COVID-19 and the economic recession.

 "I'll go through exactly the same preparation I did for the last debate, just making sure I spend a bit of time going over those issues that I know New Zealanders want to hear from us around," Ardern told RNZ.

"I see the debates as being an opportunity for us each as leaders to share our own vision and our own plans so I spend a little less time thinking about sparring with the person opposite and just directly communicating what our plans are."