Bernard Matthews is halting operations at a key Norfolk site, as it says "huge challenges" mean it is running at a loss.
The poultry producer said it is considering closing its cooked meat site at Great Witchingham following a review of its East Anglian operations, which revealed the factory is "no longer commercially viable" despite "investment and efforts to secure more business".
More than 600 jobs at the site are at risk, but the company has said that workers will be offered roles at its other factories.
Last year, the company reported losses of £10m, meanwhile in 2022 it reported losses of £25m.
A spokesman said: "We understand this will be extremely disappointing news for everyone concerned at Great Witchingham.
"This proposal is in no way a reflection of the hard work and commitment our colleagues show every day.
"If closure is confirmed, we will be able to offer colleagues alternative roles at our sister site at Holton, or across our wider group at company sites in East Anglia, where we intend to invest and grow."
They added that the company would be consulting with staff before making any final decisions.
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