What specifically was Chris Hipkins protesting in September 1997 when he was arrested?

In 2023, Chris Hipkins became Prime Minister of New Zealand, following the resignation of Jacinda Ardern from that role leading the country.

In 1997, Hipkins was part of a group of 75 Victoria University students protesting governmental education policy. They were arrested for trespassing at Parliament, though none of the subsequent prosecutions were successful. Curiously, one of the cabinet positions Hipkins would later hold was as NZ's Minister of Education.
https://www.stuff.co.nz/national/politics/3072766/Apology-for-protest-arrests-12-years-ago

In September 1997, as a first-year student at Victoria University of Wellington, Hipkins was one of dozens arrested while protesting against the Tertiary Review Green Bill at Parliament. The matter went through the courts, and 10 years later an apology and award of over $200,000 was shared among the 41 protesters. The judge ruled that despite claims by police that the protestors were violent, the protest was peaceful and there were no grounds for arrest.

https://wiki2.org/en/Chris_Hipkins+Newton