Unilever, the owners of Colman's Mustard, have confirmed they are to close their operation in Norwich.
It will end 200 years of historic mustard-making in the area although the company says it will maintain a link by opening a new mustard production, packing and milling operation in the Norwich area.
- Click to watch a report by ITV News Anglia's Helen Keenan
Unilever share a factory site in the Carrow area of the city with another food producer, Britvic, which had already announced its intention to move in 2019.
More than 200 people work for Britvic in Norwich with more than 100 other jobs at risk at Unilever.
Around 40 roles will transfer to Unilever in Burton-on-Trent and 25 jobs are expected to be created at the new milling facility near Norwich.
The GMB union said it was "absolutely devastating news" for the workforce at Colman’s, for the city of Norwich and for manufacturing in East Anglia.
The union Unite said it had vowed to fight compulsory redundancies.
Colman’s Mustard has been based in Norfolk since Jeremiah Colman started his mustard and flour business in 1814 in Stoke Holy Cross, just south of Norwich.
In 1858, the production factory moved to Norwich to its current site at Carrow Works by the River Wensum.
Colman’s became part of Unilever in 1995 when it was purchased from Reckitt & Colman. Unilever acquired the dry sauces, condiments and mustards sold under the Colman’s brand name.