A union for prison guards says a plan to triple bunk prisoners in Christchurch could put the safety of staff at risk.
The joint agency custody facility in Christchurch's new Justice and Emergency Services Precinct is designed to meet the operational requirements of both police and the Department of Corrections.
The facility is intended to act as a short-term holding facility for prisoners and for holding people before their court hearings.
The Acting Minister of Justice, Chris Finlayson, said it is unlikely that three people will be accommodated in this way on a regular basis, but police may use this option if required.
Corrections Association national president Beven Hanlon said the decision to triple bunk prisoners could put staff at risk.
He said "triple bunking" was a nice term to use during an election campaign.