Some workers at British Sugar factories in Norfolk, Suffolk and Nottinghamshire are to be balloted on strikes over pay.
The union Unite said its members will be asked to vote on industrial action after they rejected a 3.5% pay offer.
The union is seeking a pay deal in line with Retail Price Index inflation, currently 5%, plus 0.5% for the current financial year.
Sites at Wissington, near King's Lynn, Cantley, near Great Yarmouth, Bury St Edmunds, and Newark could be affected.
British Sugar said it had worked hard with unions to secure an offer it believes is fair and reasonable.
Unite's regional officer, Tony Ellingford, said: "British Sugar is a highly profitable company and despite their complaints that the sugar beet crop was hit by the bad weather during the winter, they are well able to afford a decent pay rise."
Mr Ellingford said rising petrol prices especially were hitting workers in rural areas hard.
A British Sugar spokeswoman said: "We have worked extremely hard with the trade unions to secure an offer that we firmly believe is fair and reasonable within the current economic conditions, and is above average pay awards in the external market place.
"All components of this package were recommended for acceptance by the trade unions to their members.
"Members of the GMB union have accepted the pay offer.
"However, members of the Unite union have opted to conduct a ballot to vote on industrial action and we await the outcome."
British Sugar said it had taken steps to mitigate any disruption to its four processing factories and customer deliveries.