A washing powder factory in Warrington is likely to shut because consumers are using liquid and gel capsule detergents instead, Unilever has revealed.
Persil and Surf washing powders are produced at the manufacturing giant's 136-year-old Crosfields site.
Union leaders said the move was a "hammer blow" and demanded "proper compensation" for the site's 123 staff.
Unilever announced in January that it was "undertaking a review of its future" at Crosfields.
Jon Strachan, vice president of supply chain for Unilever UK & Ireland, said: "Following the review we have, unfortunately, been unable to identify any commercially sustainable solutions for the site.
"Therefore, with regret, we are now proposing to close the factory."
Unilever said it would "do everything it can" to support the 123 employees affected.
No date has yet been given for when the plant will close, although all staff are expected to have left their roles by the end of the year.
GMB national officer Eamon O'Hearn said to see the historical site "tossed away is heartbreaking".
He added: "Unilever happily exploits its historical legacy but for its UK manufacturing workforce that is increasingly ringing hollow."