The National Party have released a new policy that would cut jail-time for prisoners who have completed rehabilitation programmes.
The Positive Pathways programme would make low-risk prisoners eligible for an earlier release, if they successfully complete training and treatment plans.
It would allow offenders to cut a maximum of 10 percent more off of their sentence than under current settings.
"Rehabilitation programmes work, so we want more prisoners to complete them," National Party corrections spokeswoman Louise Upston says.
An extra $48 million will be invested to open up another 6000 places for the programme. Ms Upston says the early release promise will be an incentive for prisoners to take part.
However, Ms Upston says they're "not making sentences shorter" instead, allowing offenders to "serve a greater portion of their sentence in the community".
"Public safety will always remain National's bottom line but in many cases public safety is enhanced by undertaking rehabilitation programmes, and controlled release into the community."
David Seymour announced earlier this year a similar policy which would see shorter sentences for prisoners who complete literacy, numeracy and driver licencing courses.