Enrolments are being keenly watched because of Labour's call for a "youthquake" which could swing the election in its favour. A surge of young voter enrolments were credited with lifting British Labour leader Jeremy Corbyn to the brink of a huge upset in the British election in June.
Ardern campaigned in Wellington yesterday, including a speech before a crowd of 500 students in Victoria University's quad.
"What an amazing day to vote," Ardern said, referring to the 124th anniversary of Women's Suffrage. She asked how many had cast early vote, and about a third of the crowd lifted their hands.
"This is an election about you," she said. "This is our chance to say that we can be a country where things keep being better and better for your generation rather than worse.
"And at the moment we're at a fork in the road where we will either walk down a path where things aren't better or where things are."
She made her pitch to young people: warm, dry homes, free tertiary education, $50 more a week for student costs, and action on climate change to reduce debt on future generations.
Green Party candidate Chloe Swarbrick, who was also at the university, said the lower youth enrolment figures were at odds with the excitement and political engagement she had witnessed at campuses around the country.
She had noticed, however, that "huge numbers" of young people still did not properly grasp the MMP system, and she spent much of her campaigning giving them a civics education.
When Swarbrick joined the Greens, she said, she had hoped to address the perpetual issue of low turnout among young people.
To do this, she has a 12-strong team aged under 30, and has been throwing gigs to try to appeal to hospitality and retail workers who are less likely to vote than university students.
Curia Market Research principal David Farrar, who polls for the National Party, said his analysis showed enrolment for people aged between 18 and 29 was about 2 per cent down on the last election.
"The big growth is the over-60s," he said. "So on the enrolment side there is absolutely no evidence for youthquake."
He said there were two caveats. Now that people were able to enrol and vote at polling booths there could be a rise in youth numbers in the last week before the election.
Also, enrolment is not a precise guide to final turnout. It was possible but not probable that final turnout could be higher than 2014 even if enrolments were lower, he said.