Shadow Foreign Secretary Yvette Cooper has said the closure of a chocolate factory which makes the world-famous After Eights is "grim news for the workforce in the run up to Christmas".
Confectionery giant Nestle has announced it will close its factory in Castleford, West Yorkshire, which is in the heart of Ms Cooper's constituency and employs 210 people.
The plant makes a range of well known products including After Eights and Toffee Crisp bars. Nestle said it is moving production to existing plants at Halifax, West Yorkshire, and Newcastle.
The firm has said it hoped to be able to offer Castleford workers posts elsewhere in Nestle. The shift in production to Halifax and Newcastle is expected to produce 120 new posts at these locations.
But unions said the closure of the plant in 2012 will see the departure of the last big manufacturing works in Castleford - an area which was badly hit by the pit closures of the last 30 years.
Ms Cooper, who is the Labour MP for Normanton, Pontefract and Castleford, said: "This is a big blow for Castleford, and is grim news for the workforce in the run up to Christmas.
"It is particularly worrying that private sector jobs are being hit, when we know big job losses are also coming in the public sector. Our area must not be abandoned like it was in the 80s and 90s.
"I've spoken to union representatives and Nestle about the Castleford factory. I think it is important local workers are given first choice of the new jobs in Halifax and offered any training and support they may need to find new jobs with other local businesses."
Ms Cooper has been the local MP since 1997.