Beer workers at the Carling plant in Burton-on-Trent, are to hold a strike ballot later this month.
The union Unite claims more than 400 staff at Molson Coors could be sacked after June 10, and reinstated on less pay.
The union says nearly 200 workers could lose as much as £9,000 a year in wages.
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Dry overnight with clear spells.
Dry on Thursday. Best of the sunshine in the morning.
A19-year-old man has been arrested and a motorcycle has been seized in connection with the incident.