UK-based salads and sandwiches manufacturers Solway Foods will close its Corby factory in Northamptonshire with the loss of 900 jobs.
Last week, the company had made 500 jobs redundant, and said that the remaining 400 would be laid-off with the plant closure in August.
Consultation on the plant closure commenced in February.
The company said that the closure-affected staff will be assessed to find new jobs, and will explore options to redeploy them across its parent 2 Sisters Food's operations.
Solway Foods runs facilities in Nottingham and Manton Wood, Nottinghamshire, and Heanor, Derbyshire.
A spokesman said, "During consultation we have fully explored all the options available to us. Sadly, the fact remains that the site is no longer viable."
Corby and East Northamptonshire MP Sawford said, "Various offers were made to support the company, including an offer to help with relocating to a new site in Corby and I am disappointed that Solway were not prepared to look at this option."
Established in 1988, Solway Foods has annual turnover in excess of £130m.
