Factory machine operators Teresa Gooch (45) and Donna Bouma (56) have worked at the factory for 16 years.
Ms Bouma said the workers were "absolutely devastated" about the proposal to close the factory.
"The crew were shocked — it’s just unbelievable and very surreal," Ms Bouma said.
The workers were prepared to "fight" the proposed closure.
"We are hopeful."
Ms Gooch said their chances of keeping their jobs "did not sound very good" and staff were feeling "raw" and hoped the workers would unite.
"It’s hard to step away from your emotions — hopefully we’ll all fight and have a chance to win," Ms Gooch said.
Ms Bouma said the emotion had got the better of "a few" staff who did not go to work yesterday. Ms Gooch said factory management had been supportive.
"The company have been really good and not worrying about production at this time ... the company are quite happy to let us deal with our emotions," Ms Gooch said.
However, next week production would return to normal, she said.
Ms Bouma said the workers had received scores of messages of support from across New Zealand.
E Tu organiser Mike Kirwood said Mondelez International Australia and New Zealand gave the union a formal proposal at a meeting at the factory yesterday and discussed it.
The meeting yesterday had "a couple" of heated moments, he said.
"We told them we weren’t happy."
The union would "pick the proposal to pieces" and challenge them on it at a meeting with Mondelez on Tuesday. The union would set timelines with Mondelez at the meeting.
Mr Kirwood would not reveal any other details of the proposal but vowed to fight it.
"It’s consultation and we will challenge what they are putting forward ... we would like to see it stay open but there is a lot of work to do yet."
