The Corrections Department is proposing to axe 11 job training positions at Tongariro/Rangipo Prison in the central North Island.
Corrections said it was investing $22 million in a trades training hub at the prison, with a focus on hospitality, light engineering and construction.
It said this would create five new instructor positions.
Corrections Association industrial officer Beven Hanlon said the positions going were mostly in forestry and farming, which meant prisoners would miss out on the opportunity to learn valuable skills.
"More and more prisoners [at] Tongariro/Rangipo are from that area, and the predominant job or work for them there is forestry or farming. Essentially, that's being shut down."
Staff have until 10 September to offer feedback on the proposal and a final decision is expected on 17 September.