ACT's David Seymour has labelled Labour's tertiary pledge "the most insidious policy" that the party "are offering this election" during tonight's 1 NEWS Young Leaders Debate.
The Labour Party says they will offer a free first year of post-secondary school education in 2018, and an extra $50 a week to student allowances if elected to Government.
Ms Ardern said this policy will be extended to two free years of post-school study in 2021, and three free years in 2024.
Taking aim at the policy tonight, a fired up David Seymour said it's "a lie" if Labour says "that education is going to be totally free."
"You're going to pay for it in your taxes and if you're dumb enough to vote and be bribed with your own money, then I don't know if university is for you," Mr Seymour said.
"The second thing I'd say is that you get what you pay for and if university is free, I guarantee you the Labour party will put in cost controls, they'll dumb it down, and university will become another three years of high school.
"You've already got universitys like this one sliding down the world rankings and if you start making it entirely state funded, if students have no skin in the game what so ever, then you are going to dumb it down further.
"It is actually the most insidious policy that Labour are offering this election and it's actually going to hurt the people."