Education providers are concerned Labour's big tertiary study promise may lower the quality of teaching.
If elected, Labour would roll out a year's free tertiary education in their first term. That would increase to two years if elected to a second term, three years if there was a third term.
Leader Jacinda Ardern also announced a $50 a week boost to student allowances if the party wins office.
While Universities New Zealand executive director Chris Whelan told The Am Show it's great to encourage more students to get a higher education, he fears institutions won't keep up.
"We are worried that this does miss out actually funding for institutions who actually have to maintain quality of teaching to more students."
"We're now almost half the funding-per student of the United States. We now get funding at the same level as countries like Bolivia, Colombia and Brazil. So we're struggling to keep up with the rest of the world in terms of maintaining the quality of our education system."
Mr Wheelan says he doesn't expect it to have a huge impact on numbers overall, as there has been a "big growth" already - but says he would "certainly like to see a little more of that funding".
"What we will see is a lot of people who have been traditionally reluctant to take on any type of debt, usually lower socio-economic, usually the first in the family to goâ€¦ some of those groups will probably choose to enrol for the first time."