A large march is expected at Mount Eden Corrections Facility today, with anti-prison group No Pride in Prisons protesting against the growing population behind bars.
New Zealand's prison population is around 10,000.
"Prisons don't do what they say they do," says spokeswoman Emilie Rakete says.
"Corrections says that prisons rehabilitate people, but the reality is that prisons are violent."
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.
The march will start at Aotea Square on Saturday at 12pm, before leaving for Mount Eden Corrections Facility. Labour Party MP Kelvin Davis, Green Party MP Marama Davidson and a member of Vicki Letele's family will all speak.
"The Government is wasting money locking 10,000 people away while inequality worsens," says Ms Rakete.
The new facility at Waikeria is being built to handle the large influx of prisoners at Mt Eden Corrections facility.
"The obvious solution is to repeal the Bail Amendment Act and cancel the construction of the prison," says Ms Rakete.
"After harsh bail restrictions were passed in 2013, the population of prisoners on remand has ballooned. Most people on remand have not been found guilty of anything and may never be found guilty.
"Rather than deal caringly and intelligently with people who have been accused of social harm, the Government has chosen to cram them into overcrowded, violent, unsafe environments."