Labour leader Jacinda Ardern is already pouring cold water over New Zealand First's plans to "stop punishing smokers" and cut tobacco taxes.
Ardern, who was with her finance spokesman Grant Robertson in Palmerston North this afternoon, said she would not consider such a policy if she is re-elected.
Usually Ardern makes a point of not ruling any post-election deals in or out ahead of possible coalition talks.
In fact, Ardern said this was something Peters "has always disagreed with".
On January 1 this year, the tobacco excise increased by 10 per cent – according to Statistics New Zealand, a single cigarette now costs almost $2.
In a statement this afternoon, Peters said the Government's target of having New Zealand smoke free by 2020 wasn't working.
He said it was actually a "contradiction and hypocrisy" for the country to be having a referendum on legalising recreational marijuana while that smoke-free target is in place.
"New Zealand First will lower tobacco excise so that the average pack of cigarettes is no more than $20, remove tax from smoking cessation tools, and put a stop to the belief that what we're doing is working," Peters said.
"The workers and poor people in this country are being screwed over to prop up our health system," he added.
Higher cigarette prices are fueling more robberies, he said, adding that his party would make alternatives more affordable.
"We want to fund more addiction services and make more smoking alternatives available." The Taxpayers Union has come out in favour of Peters' policy, calling it a "courageous stance for taxpayers".
Last week, Peters was caught smoking at Otago University's Dunedin campus, breaking its no-smoking rules.
Asked today if she would like to see Peters stop smoking, Ardern said that was a decision for him and she had never spoken to him about this habit.
Later on in the press conference, the Labour leader was asked if she agreed with Peters' comments that this has been a one of the worst campaigns in a long time.
Before she could answer, Robertson cut in: "Is that because of the price of cigarettes?"