The union said CEE planned to close its direct store delivery operation resulting in 288 redundancies. Of the total, 160 are Unite drivers and warehouse workers.
The affected sites include Bristol, East Kilbride, North London, Northampton, Sidcup and Wakefield.
Jennie Formby, Unite national officer for food and drink, said: “This news will be a devastating blow for our members and their families, especially in the current economic climate of austerity, welfare cuts and now rising unemployment.
“It is too early to make a detailed analysis of the announcement. However, our immediate priority must be to get full details of the reasoning behind this decision and to examine what alternatives there could be for our members.”
Formby added that CCE was a highly profitable and successful company and pledged that the union would do everything in its power to protect jobs.
A CCE spokesman told FoodManufacture.co.uk: "Following a strategic review, we are proposing to end our direct delivery service in Great Britain. This service is primarily used by foodservice outlets and we have identified the need for a more efficient way of distributing our products to these customers."
The firm expects to end its direct delivery service towards the end of the year, after introducing alternative distribution arrangements for customers.
CCE pledged to minimise redundancies as far as possible and support colleagues affected by the restructuring.
CEE workforce in Great Britain numbers 4,400.