On the last day of the campaign, Bill English told reporters he would try to form a government even if Labour and the Greens get more support than National on Saturday night.
He says he'll act on the presumption that the single party with the highest vote should form the Government, and he would set about doing that.
"What's happened in the past in New Zealand is that it is the party with the highest vote has been the one that's formed the government," he said.
He acknowledged that other parties were free to have a go at it as well.
On current polling, neither National nor a Labour/Greens alliance will have enough seats in parliament to form a government without bringing Winston Peters' NZ First into a coalition.
Labour leader Jacinda Ardern spent part of her last day batting away National's suggestions that interest rates would rise if her party borrowed money to pay for its promises.
She said the current Government had borrowed heavily without affecting interest rates.
"It's sad to see on the last day and the final opportunity to make a pitch to voters that we are still seeing scaremongering from the government," she said.
"I think it's because they don't want to talk about their record."