The Ministry of Education is planning to cut nine jobs from its payroll unit as staff struggle to deal with the Novopay teachers' pay debacle.
PSA national secretary Brenda Pilott said a restructuring proposal would reduce the number of positions from 23 to 14.
''It claims the staff will not be needed once Novopay is operating smoothly. The timing of this beggar's belief," she said.
"Everyone knows that the Novopay system has been a debacle and with the magnitude of the problems, who knows when it will be properly up and running."
She said the staff in the payroll unit have been putting in long, stressful hours working alongside Novopay trying to pick up the pieces.
''In the face of all this they're now being told they're facing a major restructure and a proposal which will see jobs being disestablished from March next year."
Staff had been given a two week consultation period to respond to the proposal.
Labour state services spokesman Chris Hipkins said the decision was ''mind boggling''.
''Just at the time these staff are working around the clock to get people paid they are now being told their jobs are at risk. The judgement of whoever decided this restructuring was an appropriate thing to do now is clearly flawed.''
Pilott said while payroll staff knew a review was likely at some stage, they had been completely blind-sided by the insensitivity of the timing.
"They feel that their focus on trying to sort out Novopay, especially in the lead-up to the Christmas pay period, will compromise their ability to take part in the review process. The Ministry needs to acknowledge the context of this review and delay it," she said.