NZ Election 2020: Jacinda Ardern, Judith Collins face off in The Press Leaders Debate

Labour leader Jacinda Ardern and National leader Judith Collins are going head-to-head in The Press Leaders Debate.

The debate is being held in Christchurch - the only South Island debate - and it is being moderated by The Press editor Kamala Hayman and Stuff's political editor Luke Malpass.

What you need to know:

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These live updates have finished.

9pm - Speaking to media after the debate, Ardern says it didn't get too raucous for her tonight and she enjoyed it.

"The size of the audience makes a difference, the fact that in the audience you had a lot of participation - that is something you see with The Press debates," she said. There were 750 in attendance.

She says National's economic plan "doesn't add up".

"You cannot reduce debt, also have tax cuts and claim you're maintaining services."

Ardern also spoke briefly about her car, which is an electric vehicle.

"When you're talking about a $60,000 price point, that is significant for people."

Collins says it was a "very good debate".

"I think that politics won [the debate], I thought we both did very well."

On the quickfire round, she defended both her and Ardern's ability to guess the price of common household items.

"I'd say the leaders of the two major parties are on the road almost every day and every night and we hardly ever get home. So I tell you what, I'd say that Miss Ardern and I probably haven't been doing the shopping lately."

On conversion therapy - something Labour announced it would ban if elected - Collins says she'd like to know more about it before making a decision to ban it.

"It seems to me that anybody who holds someone against their will is clearly breaking the law anyway, so I don't even understand why anyone would want to do conversion therapy. I think you are what you are or who you are."

8:33pm - We're onto closing statements.

Collins says this is the most important election in a generation.

"We're going to have to think much further out than just an election date."

She also touted National's tax cuts policy, building infrastructure and building a second harbour crossing in Auckland.

Ardern says the questions New Zealanders are facing at the election are, "who's better placed to keep New Zealand safe and who is better placed to get us on track to recovery".

"Right now, we need a strong and stable government and a clear path forward. That's what I'm offering and that's what Labour's offeirng."

8:27pm - On reducing house prices, Ardern says she will increase housing supply but didn't commit to reducing house prices.

Collins says she will get rid of the RMA.

Ardern says she "won't give up trying" to get first home buyers into houses.

8:24pm - This is a cost of living quickfire round.

For a two kilo leg of lamb, Collins said it costs $28, Ardern said it's $20. The actual price is $40.

Both correctly said the cheapest Netflix monthly subscription price, which is $11.99.

Both also correctly said that the starting salary for a teacher is $49,000.

8:22pm - We're moving on to the fifth and final section of the debate, which is about Oranga Tamariki and child uplifts.

Collins says children shouldn't be at risk in their own homes. She pointed to National's 1000 day policy. She adds she doesn't want "children killed in their own homes" and wants children safe regardless of their background.

Ardern says "everyone wants a child to be safe".

8:17pm - Both said no to a universal basic income.

8:16pm - On reducing New Zealand's suicide rate, Ardern says mental health services need to be there earlier for people who are struggling.

Collins says there needs to be a minister for mental health.

8:13pm - To get New Zealanders out to vote, Collins says the best thing is to show them politicians are "having fun".

Ardern says young people want to see action on climate change and work on child poverty.

"They care about the major things that are affecting the next generation."

8:11pm - Collins says her largest climate change policy will be National's tech policy.

Ardern says the Zero Carbon Act will make the "single biggest difference", but she says it's important to look at every sector. She also says she "doesn't know how data centres" are going to help climate change.

8:09pm - Ardern has again dodged answering whether she supports legalising recreational cannabis.

8:05pm - The leaders have taken the stage again.

7:54pm - There is a half-time intermission at the debate.

7:53pm - Ardern says she would "happily" talk to National about a four-year parliamentary term. Collins says a referendum is needed for any major constitutional reform.

On New Zealand potentially becoming a republic, Collins said the country is "moving that way". Ardern says it will happen "in my lifetime".

7:50pm - Collins says New Zealand is already leading the pack when it comes to climate change.

"Our emmissions is 0.17 percent of the world's emmissions," she said.

Ardern says New Zealand is leading the pack because the country "is doing its bit".

"We are leading the world because we have a Zero Carbon Act. We are leading the world because we are having carbon budgets and we have stopped future oil and gas permits in New Zealand."

7:46pm - Leaders are talking about the type of cars they own - Collins has a petrol car and Ardern has an electric vehicle.

Ardern says while EVs have low emissions, they are "out of reach" for New Zealanders.

"I want them to have a choice of safely cycling, of a low emmissions vehicle," she says.

Collins says she prefers EVs because the electricity lasts longer compared with hybrids.

7:42pm - The topic has moved to roading.

Commuter light rail that Labour promised in 2017 is still something that Christchurch could have "if it wanted it", Ardern says.

On National's four-lane highway between Christchurch and Ashburton, Collins says the people of Canterbury "need" that road.

7:35pm - On the DHB crisis in Canterbury, Collins wouldn't commit to sacking the board, but instead said "you'd have to start again", referencing the relationship between the DHB and the Ministry of Health.

She also says "every single year" National was in government it put money into DHBs.

Ardern says she wouldn't get rid of the board, and that the problems it's seeing reflects what is happening at every DHB.

7:31pm - Both leaders said "no" to a sugar tax. Collins says she thinks "education is better".

7:29pm - The debate has moved to a section on issues in Christchurch and the South Island.

Collins says she would "ensure" a Bill would pass that would put fluoride in water. Her answer was in response to a question from a Christchurch resident about the number of children with teeth problems in the city.

Ardern says she supports fluoridation for keeping teeth healthy.

"You need to put it in your water or it is painted onto children's teeth," she says.

Instead, she says Labour will roll out healthy lunches to 200,000 pupils.

7:25pm - On tourism in the pandemic, Collins says the international tourism sector will take "some time" to come back, but domestically people aren't "feeling happy".

7:22pm - On the $8 billion hole in National's finance plan, Collins didn't admit to it, instead saying that she can be trusted because she was honest about the first $4 billion hole.

7:19pm - The questions have moved to the economic response for COVID-19.

Ardern says Labour's approach is "better" than National's because "investing in infrastructure creates jobs".

She also says she wants to support small businesses, and that a tax cut is "unaffordable".

Collins replied that tax cuts are what New Zealanders need.

7:14pm - The first section of questions is about COVID-19 and New Zealand's recovery.

Ardern was asked what she would've done differently in dealing with the virus if she knew back in March what she knows now - she said she may have acted earlier.

This caused Collins to say that National were the party who were more serious about COVID-19, including raising issues about masks and wanting to close the borders earlier.

"We didn't go fast and hard and early, Samoa went hard and early," Collins said.

Ardern replied that that is incorrect, and Collins replied: "Don't disrespect Samoa."

"We have been criticised by the National Party at every step of this response," Ardern replied.

7:10pm - Ardern and Collins have taken the stage and they are giving their opening statements.

Collins says this is the "most important election" New Zealanders have ever faced.

"The most important issue for this election is about the economic recovery for New Zealand. New Zealand is not unlike every other part of the world."

She also briefly outlined National's economy policies, which include tax cuts.

"We need to build for the future, not look back at the past."

Ardern acknowledged the crises that Christchurch has faced over the past decade. She says Cantabrians are a model for rebuilding after a crisis. 

7:05pm - The leaders have taken the stage and are about to give their opening statements.

6:50pm - Jacinda Ardern has posted a selfie ahead of the debate.

"Backstage at the Christchurch Town Hall preparing for the Press Debate! Tune in online at 7pm if you're keen to join us for another full 90 minutes," she said.

6:40pm - Judith Collins posted a photo to Instagram earlier on Tuesday of her at a podium getting prepared for the debate.

"Ready for tonight! Round three," she captioned the post.

6:35pm - Newshub's political editor Tova O'Brien says Tuesday's controversy with the leaked email from National MP Denise Lee is "turmoil" for the party.

Lee sent an email - which was later leaked to Newshub - to her National Party colleagues on Monday, describing an announcement Collins made to review Auckland Council as a "highly problematic idea" and panned it as "another working group".

Lee, who is the Opposition's spokesperson for local government in Auckland, also took issue with Collins bypassing her altogether during the decision-making process. She described it as "incredibly poor form" and "a shockingly bad example of poor culture".

O'Brien said the fact it's happening now before election day, and not afterwards, is "about as bad as it gets" for National.

"This is a real pivot point in the campaign and it happened just before Jacinda Ardern and Judith Collins square off for the Christchurch Press leaders debate."