Cabinet papers show the government continued work towards a mega-prison at Waikeria for months after taking power.
Corrections Minister Kelvin Davis ultimately pulled the brakes on the billion-dollar project and last month instead greenlit a smaller 600-bed facility.
However, documents - released on Tuesday - show that in December last year, Mr Davis recommended continuing work on the mega-prison until at least March given the severe lack of prison beds.
"The only sensible plan of action at this point is to maintain course and progress on the Waikeria Corrections and Treatment Facility. I recommend that we continue to implement the current project plan," Mr Davis said.
"We can then make our final decision ... in March 2018 based on the best options to reduce the prison population."
Mr Davis could not be reached last night for comment.
National's Corrections spokesperson David Bennett said the government did not know what it was doing when it came to law and order.
"The best information is in front of [Mr Davis] in December," Mr Bennett said.
"He's had numerous reports saying that there is a massive shortfall in what's being provided in terms of capacity and he's failed to act on that."
Mr Davis ultimately made the wrong decision in downsizing the prison build, Mr Bennett said.
"As a result our communities and our prisons and the staff in them are less safe."