Jacinda Ardern, Judith Collins have seemingly endless promises to keep after Newshub Leaders Debate

The leaders of Labour and National brought fire, surprise and humour to the Newshub Leaders Debate - now the only problem for Jacinda Ardern and Judith Collins is to keep the seemingly endless stream of promises they made. 

With a hiss and a roar, they were off - Ardern and Collins went head-to-head on Wednesday night in their second election campaign TV leaders debate, hosted by Newshub's national correspondent Patrick Gower. 

The debate had its fair share of drama, with Collins turning to Ardern at one point to say: "Ms Ardern you've had your turn... manners."

The pair were often desperate to get a word in, and Ardern didn't hold back from making sure she was heard this time. 

"A little good behaviour on the stage if I may," she directed at Collins, who reacted with a gasp.

Ardern even accused Collins of having "no credibility" at one point, forcing Gower to intervene. 

"I've got break this up - it's like the Comancheros versus the Mongols out here," he said. 

The ultimate gang war - and it didn't stop there: Then came the change of plans. 

Ardern was asked if she would declare a climate change emergency, and she told Gower she "would have no issue" with that.

He asked the Labour leader if that was a promise and she said "yes". 

It was one of a raft of new policy promises from the debate. 

The big bang from both Ardern and Collins was their support for an investigation into Pharmac's funding of things like cancer drugs. 

"Yes we will - I think we should," Collins said. 

"If it gives people faith in our system, then yes," Ardern said. 

For Collins it's personal, as she reflected on her own family connection to cancer. 

"My brother-in-law was like some other people who couldn't even get in because of the lockdown and got told over the phone he had terminal cancer," she said. 

Ardern surprised the crowd of 100 socially-distanced undecided voters by finally opening up on getting high. 

"Jacinda Ardern, have you ever smoked cannabis?" Gower asked her. 

"Yes I did a long time ago," she replied. 

But Ardern still won't divulge how she's voting in the recreational cannabis referendum. 

"I'll be giving my answer after the election, after New Zealand has decided," she said. 

Collins says New Zealanders "deserve an answer" and "deserve a straight answer, not waffle". 

New Zealanders did finally get some straight answers - the gun register included in the second tranche of gun law reforms would be gone under National. 

"The gun register is gone under National," Ardern said, shaking her head in disapproval. 

Collins responded, "Well clearly it is because it hasn't gone anywhere under you."

Also apparently gone would be those occupying the land at Ihumātao. 

"They should get off that land and I'm not paying a cent of taxpayer money for it," Collins said. 

Compulsory te reo Māori in schools is in under Labour, with Ardern confirming it's in her heart. 

"Yes, it is," she said. 

To the businesses who rorted and pocketed the wage subsidy, National is coming for that cash, according to Collins. 

"Well, we may have to change a law," she said, going on to describe the Government as "naïve" over the way it rolled out the wage subsidy scheme. 

There are some things they both want, including to be in power for longer. Ardern and Collins both think Government terms should be extended from three years to four. 

The pair also agreed on the need to eradicate period poverty, with sanitary products fully subsidised for every woman and girl. 

"Yeah actually, yes I think we should," Ardern said. 

"I don't have any problem at all with agreeing on in terms of schools," Collins said. 

Every school also gets gender neutral toilets for transgender children under National and Labour. 

"Every child should be able to go to a bathroom they feel comfortable going to," Ardern said. 

"Yeah, it's just one bathroom for goodness sake," Collins said. 

And no matter who's in power, Parliament gets a full blown statue of Kate Sheppard, who led the women's suffrage movement in New Zealand.

"Of course we should," Collins said. 

"Yes, why not," Ardern said. 

ACT leader David Seymour could be Deputy Prime Minister under Collins, and apparently a good one - but Ardern doesn't seem too keen on the idea. 

"He'd be excellent in my opinion," Collins said. 

"Jeepers," Ardern said. 

If Collins is Prime Minister, she confirmed: "I'm not into communism."

She's also coveting the role of cover girl too, after Gower asked if she would seriously say no to be able to feature on the cover of Vogue as Ardern once did. 

"Oh no, absolutely would I like to be there - there's no problem with that," Collins said, as the crowd laughed and cheered. 

The leaders have laid out the options for New Zealanders ahead of October 17.

"The world is changing; unfortunately Judith Collins does not want to change with it," Ardern said. 

"If Jacinda Ardern is going to use my age against me, I'm happy to use my experience," Collins retorted. 

Now it's up to you to decide.