McCain Foods is closing the vegetable processing line at its Timaru plant with the loss of 30 jobs.
The Engineering, Printing and Manufacturing Union (EPMU) said many of the workers will be able to get jobs at a french-fry line at the plant.
McCain Foods Australia/New Zealand managingdirector Steve Yung said flat domestic sales, an ageing plant and declining exports to Japan, China and South East Asia contributed to the decision to close the plant, the Timaru Herald reported.
The plant employs about 240 people of which 30 worked on the vegetable line.
EPMU organiser John Gardner said many of the workers would have the opportunity to work on the french-fry processing part of the plant but workers would have to work 12-hour shifts instead of eight-hour shifts.
"My gut feeling is that only about a quarter will accept because many find the 12-hour shifts hard," he said.
He said workers were not surprised to hear the vegetable processing line was closing as it had not been working at capacity.
"Any plant closure is a regrettable situation but we will be closely consulting with the company up until the November closure in order to ensure we get the best possible outcome for our members.
"There has never been a question about the quality of the work or the product from the Timaru site but from what we understand it was chosen for closure as it is the least efficient McCain processor in the country due to aging plant and equipment."
