New Zealand Dairy Workers Union national secretary Chris Flatt said the union had been briefed on behalf of its Hokitika members but it was still working through the detail.
"What we've been informed is that we'll have people under our collective who will be affected," Flatt said.
"I'm not in a position to say exactly who yet and there hasn't been a formal announcement yet. We are aware of affected workers. We can't reveal numbers or any positions yet."
The union covers about 230 staff at the Hokitika site and a further 30 at Rolleston and represents non-salaried drivers, dairy processing operators, stores workers and laboratory staff.
Flatt said he expected "a plan for a formal notice" to emerge from the Hokitika site either today or tomorrow.
The union had been working closely with its members and the company around "various options".
This included which positions might be affected, what the options were for continued employment at the factories for those affected, and the potential for staff in other unaffected positions to take the opportunity to leave, thereby opening up vacancies for staff who might otherwise be redundant.
As far as the union was concerned "potential redundancies" included jobs not covered by the union's collective contract.
"We are aware now that there are actual members under our collective who are affected by the proposed review."
The union fully understood the likely economic impact on both Hokitika and Greymouth of potential job losses, Flatt said.
Shareholders contacted today were in the dark at this stage.
Whataroa farmer and shareholder Phonse Carroll said it was to be expected that staff below the management level might be affected, with factory level jobs under the gun, although the company had said the review was broader.
"They went to great lengths it was across the board. It doesn't surprise me to be honest," he said.
"I do know that we've got a couple of reasonably good guys there looking at that side of things - how the plant's working and how many are actually needed."
Carroll said this was the latest of three staff reviews in four years of "stripping out the dead wood" but it may still be too late.
It was likely new chief executive Toni Brendish had found things were far worse than she might have known, while the shareholders like wanted the factory to be contributing more to the local economy and "not hurting people out there".
"I think she's realised she's in a position now that it's a lot worse than she was led to believe."
- Greymouth Star