Other parties, including the Greens and Labour, have promised to reverse cuts made to student support under National, including to post-graduate student allowances.
However, they have said free tertiary education is not affordable.
Ms Harre insisted that it was, even with today's pledge to also pay universal student allowances and other measures including a plan to forgive some of the existing student debt.
She said the abolition of student fees and the universal student allowance would cost around $1.2 billion a year. The figures came from the Government's own books and other research and were absolutely accurate, Ms Harre said.
They were based on current student numbers.
Ms Harre said the scheme was a matter of priorities, not affordability. National have indicated that it expects to have $1.5 billion available for tax cuts in 2017, she said.
"At some point we have to accept that the debt mountain is a drag on our whole society." The internet Mana Party also wants to develop a "debt forgiveness plan".
That would see repayment thresholds immediately increased, and those on parental leave would have their debt repaid by the Government at the average rate for the year prior to them taking leave.
Ms Harre said they would eventually look at wiping or reducing some other borrowers' debt. Further work and research was needed to determine how this might happen, but it could be done based on income.
Internet Mana also want to create a summer jobs programme for students.
Asked about the Green Party's recent comments about working with National under a memorandum of understanding, Ms Harre said they needed to "seriously consider their strategy over the next eight days".
"I would like to see them joining the rest of us in growing the momentum that has already started.
"We know that the momentum is already there to change the Government. The voter turn-out is going to determine the election."
INTERNET MANA'S TERTIARY POLICY
• Abolish fees for study at public tertiary institutions.
• A universal student allowance.
• Establish a new summer jobs programme for students.
• Develop a "loan forgiveness programme" for those with existing debt.