However, it is not clear if jobs will be lost if the closure goes ahead.
The site, which employs just over 240 workers, is earmarked for closure by the end of 2019 following a detailed review of Britvic’s production plants and distribution network.
A spokeswoman said there should be no issues with supply of Robinsons and Fruit Shoot drinks, which are produced there. “It’s a proposal so if it is agreed production will be moved in a phased approach to other sites, but for now manufacturing will continue at the Norwich site.”
She added that as the closure was currently a proposal she could not say whether any of the workers would be offered alternative employment should production at Norwich cease.
Britvic has other sites in east London, Leeds and Rugby.
Norwich MP Clive Lewis is committed to stopping the closure, according to the GMB union, which has more than 150 members working at the site.
The union has a meeting with Britvic on 27 October. Regional organiser Ivan Mercer said he did not think any jobs would be transferred should the closure go ahead, as he claimed there were very few vacancies at other sites.
Britvic chief executive Simon Litherland said the proposed changes presented significant productivity and efficiency savings in its manufacturing operations.
Mercer acknowledged that the investment Britvic is putting into its other sites will make its production lines more efficient and more cost-effective, but added: “Which means they need less people to run them.
“The simple truth is that the movement of the lines from Norwich to the other sites could also result in job losses at those other sites.
“It's something we can’t rule out. It's a fear we’ve got.”