NZ Election 2020: Judith Collins explains why she called Jacinda Ardern 'dear'

National leader Judith Collins has defended using what have been described as patronising comments towards Jacinda Ardern, saying it's because she doesn't like to "hear slogans being thrown around".

During the Newshub Leaders Debate on Wednesday, Collins replied with "what for, dear?" after the Labour leader asked her what her plan for tackling climate change is.

The pair were discussing last year's school climate strikes and declaring a climate emergency in New Zealand. 

Ardern said she'd have "no issue" with declaring a climate emergency after it was previously voted down in Parliament last year.

"It is an emergency and everything we've done demonstrates that," Ardern said.

"An emergency in real terms means stopping future offshore oil and gas exploration."

Collins took issue with stopping oil and gas exploration, claiming "coal use has gone up".

"So now we've got more coal being used instead of natural gas to actually create electricity," she said.

"All the talk, all the fluffing around about emergencies, tell you what, actually, it's got worse not better under this particular leader."

Ardern then asked Collins, "What is your plan?"

"What for, dear?" Collins replied.

"Climate change," Ardern said.

Collins said her plan is to support New Zealand farmers by "giving them the science" to help them cut carbon emissions.

"What we do not do is that we do not beggar them and our country to an order so that we can go and get a photo op somewhere," she said.

In a post-debate discussion with Newshub political editor Tova O'Brien, Collins was asked if she worries about coming across as patronising when she uses phrases like "dear" and calling Ardern "naive".

"I'm just myself, you see, and part of that is that sometimes when I hear slogans being thrown around with absolutely no delivery... I do actually find it a bit galling to be given yet another slogan, whether it's about child poverty or anything else, when actually things have got worse not better after three years," Collins said.

"I think sometimes people do expect that they will not just have their slogans thrown around."