Around 100 people turned up to march alongside a prison reform group to protest against the growing number of prisoners at Mount Eden Corrections Facility.
The protest in Auckland started at 12pm at Aotea Square on Saturday and ended at Mt Eden Prison.
The group is demanding two changes: the repeal of the Bail Amendment Act 2013, which has led to an increase in prisoners being held without conviction, and a halt to the construction of a new facility at Waikeria Prison.
No Pride in Prisons spokeswoman Emilie Rakete hopes the protest will put pressure on the Government to repeal the Bail Amendment Act and cancel the construction of the Waikeria Prison.
"Prisons don't do what they say they do," she says.
"Corrections says that prisons rehabilitate people, but the reality is that prisons are violent."
But the Sensible Sentencing Trust is calling the protesters "dreamers" who "can't have it both ways".
"If they want a liberal society, crime will flourish and prison numbers will increase," founder Garth McVicar says.
He says the trust is "responsible for driving much of the legislation" the marchers are opposed to.
Mr McVicar believes the group's call for changes to the Bail Amendment Act show how "delusional, mistaken and misguided".
"These people obviously haven't done their homework or are simply choosing to ignore the facts. The typical criminal who ends up in prison today has numerous prior offences, many violent.
"These criminals simply refuse to be rehabilitated and make a deliberate conscious choice to continue with a life of crime."
Mr McVicar believes prison is "the only effective tool" to keep the community safe.