About 100 jobs could be axed as part of a restructure of Sealord's processing plant in Nelson.
The firm has just announced details to its staff this afternoon.
Sealord has today told its workers it needs to restructure the wetfish factory in Nelson through a reduction in both operations and the number of staff working there.
Sealord general manager Doug Paulin said the factory was not economically viable in its current form, and 97 jobs were at risk; that equated to 13 percent of its workforce in Nelson.
However, Service and Food Workers Union's assistant national secretary Neville Donaldson said the job losses could be higher, with more than 100 processing jobs and about 30 support staff positions to go.
Listen to Neville Donaldson
The announcement had caught everyone by surprise, and the losses would be a tragedy for the workers, their families and the Nelson community.
"What's been indicated by the company today in their announcement is that there will probably be something in the region of just over 100 processing jobs go, and then they're looking at the salaried and support staff which would amount to a further 30-odd jobs going, so it's a considerable number of staff that they're looking to reduce."
Government inaction on manufacturing was largely to blame, and the job losses were part of a disturbing trend in food processing, Mr Donaldson said. The high New Zealand dollar was also to blame.
But Mr Paulin said it might be a case of short-term pain for long-term gain.
"My hope is that we have a factory that we can rebuild, and refocus on those products where there's really opportunity for us to add value and add margin to our business," he said.
"We do that and then there becomes more jobs available, the difficulty being that the amount of sales currently, in those loss-making products, is much higher than the volumes that are in those opportunities that we see for the future."