Winston Peters is taking his campaign beyond Northland as he looks to claw back some of the support that appears to have slipped from his party.

Photo: RNZ / Rebekah Parsons-King

New Zealand First was sitting at 13 percent in RNZ's Poll of Polls in early August, as Jacinda Ardern took over as the Labour leader, but by the latest poll average it had slipped to 7.9 percent support.

Just weeks ago Mr Peters was describing the election as a three-horse race between National, Labour and New Zealand First. That was before Labour, with Ms Ardern at the helm, caught up to National and returned New Zealand First and the Greens to true minor party status.

But the New Zealand First leader said the polls were just plain wrong.

"They're sort of junk science that you [media] people persist in, and the gap between the pollsters is massive, but that doesn't stop you," Mr Peters said. "You've just had Brexit, you've just had Trump [in the] United States and you've just had Australia, all in the last 18 months, and you're carrying on regardless.

"But I'm a very forgiving person, and so I'm carrying on ignoring you all and ignoring these polls."

Mr Peters has been meeting voters in the North and South Islands as well as juggling candidate meetings in his vast Northland electorate this week.

At a Grey Power meeting in Kerikeri a voter asked Mr Peters the question he gets everywhere he goes: would he support National or Labour if he was in a position to determine the next government.

"Which media outlet do you belong to? Because for 24 years that's all they've ever asked me," he responded.

"Well here's my answer... no doctor would operate on somebody seriously unless they knew all the conditions of the patient and likewise it is in politics.

"So these people in the media who ask me... 'who are you going to go with' as though I'm a dictator - I don't know what comes next in this campaign."

In Rangiora on Wednesday, several hundred people turned out to hear Mr Peters speak.

One group of loyal supporters said they backed Mr Peters because they were fed up with immigrants and believed he would stop them.

"You've just got to go to the supermarkets and you see it, they're different - they don't look like us," said one.

"They're taking control of our country, this is the thing, and they're foreigners - very foreign, it's not as if they're English speaking people," another added.

"And you can't understand a damn word they're saying," a third said. "It makes me sick the way things are going. Why can't we just be us like we used to be?"

American Kathy Gentile, an immigrant to New Zealand who has multiple sclerosis, was delighted to learn New Zealand First supported legalising medicinal marijuana and ensuring it was affordable and accessible for people in pain like herself.

She said it cemented her view of Mr Peters.

"I've always liked him since I moved here because he's a straight shooter - like I said he reminds me of Donald Trump.

"I voted for Donald Trump, I love Donald Trump and Winston Peters is like him to me - so he's got my vote."