Alex Mayer MEP spoke in the European Parliament to support of Colman's.
She said: "My constituents are alarmed at the threat to the Colman’s mustard factory after the announcement that Britvic who share the same site are closing their operations.
“Colman’s Mustard is Norfolk through and through and Norwich is where the jobs need to stay.
“The 200 year old larder staple is quintessentially East Anglian, made in Norwich with English mustard seeds from Norfolk, Cambridgeshire and Lincolnshire. And it is enjoyed across the world.
“The decline of manufacturing jobs is not written in stone and 10,000 people have already signed the EDP petition to say we don’t want to see much-needed jobs that are vital for the Norwich economy lost. And we don’t want to see the 200-year Norwich and Colman’s link, severed.
“My message is clear Norwich doesn’t just have a fiery condiment, we have fiery campaigners too. Unilever - come back with new plans and reassurances that cut the mustard."