The Labour Party says there needs to be a bi-partisan 15-year target to reduce the prison population by 30 percent.
A Waitangi Tribunal report has said the Department of Corrections has failed Māori by not doing enough to reduce the high rates of Māori reoffending.
Labour's corrections spokesperson Kelvin Davis told TVNZ's Q+A programme the prison system had a bias against Māori and there was no plan to counter recidivism.
"We need to sit down and say 'what are we going to do, regardless of who's in government, to reduce the prison population'? So we've got 10,000 people in prison now, that means we would get down to 7000 over 15 years, there's 5000 Māori, that would mean we'd have 3500 Māori in prison."
Mr Davis said the more people that were imprisoned, the more rehabilitation programmes were needed.