The First Union is calling for Regional Economic Development Minister Shane Jones to intervene and stop any job losses at the Warehouse.
Under a proposal put to affected staff last month, up to 180 jobs may go at 93 stores.
The deadline for feedback on the proposal was reached this week after being extended a few days.
First Union organiser Kate Davis said there was confusion about who might be staying and who might be going.
"Members are calling me crying because they are hearing that some of their colleagues have been verbally told they'll keep their jobs, while others have no idea if they should be looking for a job or not."
The consultation phase had been a "shambles" and workers wanted more clarity about the changes, Ms Davis said.
"Simple things like what is the pay associated with the two new roles...they haven't even provided any kind of information around that."
The regions would be hardest hit by any job losses and the union wanted Shane Jones to step in.
"This is his area...this is what he is supposedly passionate about and he has helped out and spoken out...when they (Warehouse) tried to pull out of Kaikohe.
Mr Jones has been approached for comment.
The Warehouse declined to be interviewed, but told RNZ it would consider all the feedback from the workers and the union next week.
The company has already made changes to its marketing and human resources teams and moved its in-store strategy to an everyday low-price model.