Labour leader Jacinda Ardern says the campaign is too close to call a day out from the election.

The last poll before the election showed Labour's progress up the polls has stalled almost ten points short of National - but National also slipped back a tad, giving NZ First leader Winston Peters the kingmaker position.

As a huge campaign effort nears its end Ardern yesterday underlined the importance of young voters to Labour by visiting another university - and says she's holding up well for someone who doesn't drink coffee.

"This has been an exceptional campaign, one that will go down in history for many reasons. I'm really proud of the campaign that we have run. But really there is a sense of urgency now. My message to New Zealanders would be that we cannot wait another three years for the change we need," she said.

"My sense of urgency really is for that generation as well ... enrolment still needs to lift. My message to young voters is to vote early, vote today, vote tomorrow."

She told Focus today the party's internal polling shows the race between National and Labour is extremely close just one day out from polling day. There was as little as five points between the two major parties, she said.

Ardern said the volume of advanced voting was encouraging but urged people to enrol today if they hadn't done so already.

She criticised National for their ongoing negative campaigning and was surprised the "mistruths and lies" continued as late as Wednesday.

Ardern said this election was not about the next three years but the next decade and she urged voters not to drift on autopilot any more.

"It's tight and what I would say is that it shows that every single vote will count and that turnout will determine this election," said Ardern.

She said the country's first minority government was also on the cards.

Ardern said there were "multiple iterations" of potential coalition partners, including the Greens, New Zealand First and the Maori Party.

"I think what that says, though, is that Labour has a lot of options and National doesn't."

On the final day of campaigning Ardern said her highlight was the general mood for change she was sensing across the country.

"I sense this real motivation and mood for change, that people have really joined us in our vision for more affordable housing, more accessible health care and cleaning up the environment, so just having support for those messages generally, the turnout whenever we have put on public rallies has been phenomenal."

While praising Prime Minister Bill English for the way he handled the finance portfolio under the Key administration, Ardern today criticised his negatively focused campaign and "continual grasping on to that what was, quite frankly, complete mistruth, fake news, lies".

She said continually perpetuating falsehoods surprised her.

"I did not think he would do that," she said.

She contested a general slowdown in the economy could affect Labour's plan, saying the party had a plan around economic growth that focused on productivity and investing in research and development. That included associated tax credits instead of relying on trading real estate and immigration to boost the economy, she said.

"What I would say to voters is if you want to make sure that we don't drift on autopilot any more, that we get people back into affordable housing, accessing decent health care and cleaning up our environment, we can't afford to wait any longer. Now's our chance to tackle those issues head on. We've got a fully costed plan for it and under Labour New Zealand will do better," said Ardern.