Food manufacturer Kerry Foods have earmarked its factory in Burton-on Trent for closure, putting 900 jobs at risk.
Union officials have described the plan as a "crushing blow" for thearea.
Unite said it would leave no stone unturned in helping its members affected by the announcement, and has already been in touch with brewer Molson Coors, the town's second largest employer, regarding employment opportunities.
Regional officer Rick Coyle said:
This is a calamity for Burton as Kerry Foods is the town's biggest employer.It is heartbreaking for the workforce, their families and, more widely, acrushing blow for the regional economy.This is a very sad day for Burton and the end of an era.
Unite said the closure was a result of Kerry Foods losing its contract tosupply supermarket giant Tesco with ready-made meals
jobs are at risk at the Kerry Foods factory in Burton-on-Trent
Mr Coyle added: "The problem going forward is that there are not that manywell-paid jobs in Burton and the vicinity to replace those that will be lost atthe end of August.
"We have been in touch with Molson Coors to explore employment opportunities there. Also, we will help arrange a jobs fair at the site and assist our members with their CVs and advice on updating their skills."
In a statement a spokesperson for Kerry Foods said:
Kerry Foods announced today that we propose to cease operations at our production facility in Burton from the start of September, notwithstanding continuing efforts to find alternative solutions for the site. The company would like to extend a sincere thank you to all our Burton colleagues for their hard work and commitment and our priority now is to support all employees affected during this time.
The union said its staff will meet management on Friday to discuss an enhanced redundancy package for its members.