Heinz's confirmation that it will close its potato factory in Norfolk, a move which will result in hundreds of job losses, has been described by a trade union as "devastating".
The proposed closure of the Westwick factory in North Walsham, which employs 200 staff, was first revealed in October 2014.
The company said its licence to manufacture Aunt Bessie's frozen potato products for the William Jackson Food Group nears its end in April 2015 and will not be renewed.
Heinz previously said it was "deeply disappointed" to make the announcement but said that there is not sufficient manufacturing volume to keep the factory operational.
It added that it will now focus on providing job search help for affected employees.
The Usdaw (Union of Shop, Distributive and Allied Workers) described the news as "devastating".
Usdaw national officer David Gill said: "Confirmation of the closure is devastating news for our members, their families and the wider community, particularly just before Christmas. Our priority is to work with the company to help find alternative employment for the staff.
"We will continue in consultation meetings throughout January to agree the procedures for the expected closure of the plant in April. There is no doubt that the loyal and committed staff on-site do not deserve this, but the loss of the Aunt Bessie's contract has proved to be a fatal blow."