Video: The moment Maori Party co-leader walks off during testy live TV debate

Maori Party co-leader Marama Fox has walked out of the end of a televised debate with a tobacco company spokesman after telling him he should "crawl back into the hole that is reserved for the corporate executioners".

Ms Fox took off her microphone and left the set following a testy 17-minute talk with Imperial Tobacco's Axel Gietz on TV3's The Nation this morning.

TV3 said it had invited Mr Gietz out from the UK to discuss the New Zealand government's decision to go down the road of compulsory plain packaging for tobacco.

An impassioned Ms Fox, whose party has been fighting against the high rate of smoking among Maori, appeared fed up with Mr Gietz's arguments towards the end when he argued it was a legal product that people chose to smoke.

"Imperial Tobacco make billions of dollars every year profiting off misery and death. You are a peddler of death... and you come to New Zealand in some `public service' to help us in the debate when we already know that it kills our children.

"I am not going to listen to you. I think you should crawl back into the hole that is reserved for the corporate executioners like yourself... I am sorry, I've had enough."

Mr Gietz had earlier argued Australia introduced plain packaging at the end of 2012 but long term consumption, which was already going down, was not affected.

"What we have seen however, is a growth in underage smoking, by 30 per cent in Australia, since December 2012... there's a causal link here: we've also seen an increase in illicit trade in tobacco products."

Imperial Tobacco drew the line at plain packaging and it sued governments because it was trying to protect its brands. Mr Gietz wouldn't rule out taking legal action against the New Zealand government.

Ms Fox disputed the claim plain packaging wasn't working in Australia.

Tobacco companies were spending a lot of money fighting it because it threatened their profits, she said.

"For the last 27 years I have not attended a funeral of someone in our family - and I've attended numerous funerals - who has died of natural causes.

"They [smoking diseases] are putting our people in the graveyard, and you and your companies are addicting people to cigarettes and telling us it's their free choice and that's fine, we are going to profit off the death of your people."