The plan to turn 16 prisons into working prisons by 2017 is being labelled ambitious and some question whether it can be done with current resources.
The National Party made the pledge during this year's election campaign to get all prisoners involved with work experience, skills training and education in a structured 40-hour week.
Watch National's John Key and Anne Tolley here:
At present, Rolleston, Auckland Women's and Tongariro-Rangipo prisons get inmates involved in education, skills training and work experience for at least 40 hours a week. The aim is to support rehabilitation and reduce offending.
When announcing the plan to extend full working weeks to all public prisons, Corrections Minister Anne Tolley said it would not require any additional funding and could be developed through reprioritisation of resources.
Willie Cochrane, a PSA national organiser and former Corrections worker with nearly 20 year's experience, said many prisoners are unlocked only between 8am and 5pm and that would need to change to achieve an eight-hour working day.
"If the department was given the resources and the funding, they could go back to the old six o'clock - seven am unlock and seven o'clock at night lock-up, where you could probably fit in a structured working day.
"But what that means again, is the reintroduction of the second shift of workers - prison officers and Corrections staff."
A spokesperson for Rethinking Crime and Punishment, Kim Workman, agrees it will be hard to create working prisons without more resources.
"You know a lot of prisoners are locked up for 18 to 21 hours a day in their cells - so if they're going to work, they need to get out of the cells and that means more staffing, more supervision."
A spokesperson for the Howard League for Penal Reform, Madeline Rose, is concerned at what services the Department of Corrections will cut to free up money to create working prisons.
"Funding from somewhere else, that's how they are going to do it, so that's a bit of a worry, and Howard League would be interested to know what services are going to be removed to pay for it."
Mr Workman said achieving the goal of having all prisoners in work won't be easy. "A lot of prisoners have physical disabilities, a lot of them are mentally unwell and have psycho-social problems and don't get on with people that well, so it is going to be something of a challenge."
Ms Tolley is out of the country and was not available for comment.
Corrections' National Commissioner Jeremy Lightfoot said in a statement he acknowledges some prisoners would not be able to participate fully in the 40-hour plan. However, it is expected that all inmates would be engaged in some form of activity.