The Ministry of Education is failing to meet its obligations to find alternative roles for staff it is making redundant, the Public Service Association (PSA) says.
The union says the ministry has identified at least 605 roles to be cut so far, as part of the government's plan to downsize the public service.
As of December, the ministry employed 4509 total staff, and it was initially reported that 755 jobs were on the line.
The PSA said the cuts extended to regional offices, the curriculum centre, central services, and staff who worked directly with the education sector.
Assistant secretary Fleur Fitzsimons said the ministry had a history of relying on contractors to plug gaps, and the collective agreement set out expectations for redeploying staff.
"The ministry hasn't set up the required processes and systems to identify redeployment opportunities, either within the ministry or outside it," she said.
She said there were more decisions to be made regarding further cuts, and was expecting more roles to go.
The PSA would be requiring strict compliance with the collective agreement from the ministry around helping its staff into new roles.
"The provisions in the collective agreement are humane provisions designed to make the best use of talented education experts, and to recognise the traumatic consequences that a loss of livelihood has on people."
"Some of these people are former teachers, others are curriculum experts," Fitzsimons said. "Work is available, and people should be supported into it."
The ministry would not confirm the number of jobs it was cutting at this stage.
Ministry of Education corporate leader Zoe Griffiths said: "We are at different stages of the change process across the ministry with some decision documents released to staff today.
"Our initial proposal was for 755 FTE positions across the ministry, with 316 of these roles currently vacant and when the process is completed we will know the final number."
Griffiths confirmed they were engaging with the PSA regarding obligations under the collective agreement.