Nearly 500 jobs were under threat today after supermarket milk supplier Dairy Crest announced plans to close two dairies.
The proposed closures involve a glass bottling dairy at Aintree, where 220 people work, and a site at Fenstanton in Cambridgeshire employing 250 people.
Dairy Crest said a recent £75 million investment programme enabled it to transfer work to its three polybottle dairies at Severnside, Chadwell Heath and Foston in Derbyshire.
The company is battling an "extremely challenging" market for liquid milk and said the plans, which are subject to staff consultation, would help it reduce costs and sustain profitability.
Dairy Crest, which employs 4,000 people in its dairies business and 6,000 people overall, also announced that its current contract to supply liquid milk to Tesco will not be renewed in July.
Around 3% of the company's liquid milk sales are made to Tesco and Dairy Crest said the loss of the contract was not a factor in the decision to close the two dairies later this year.
The demise of the Aintree site reflects the fall in sales of milk in glass bottles as residential trade continues to decline and customers increasingly opt for plastic bottles and milk bags.
Dairy Crest also has a food division which makes leading brands such as Cathedral City, Country Life and Clover.
Chief executive Mark Allen said the dairy closures would protect the future of the dairies side of the business.
He added: "The decision to consult on the closure of our Aintree and Fenstanton facilities has not been taken lightly, but we believe that this proposed restructuring of our dairies business is the right decision for the long term."
Unite national officer Cath Speight said the union will be doing "everything possible" to save the jobs and maximise the opportunity for redeployment.
She added: "These closures will be a massive blow for the workers and the local areas affected. As more and more people are made redundant, job opportunities are becoming even scarcer. We now owe it to our members and their families to do everything in our power to help and support them.
"We hope Dairy Crest's management will rethink this decision and we urge them to offer the staff affected every opportunity for redeployment within the business."