China Clay company Imerys has announced that it is cutting 70 jobs.
It said the job losses were the result of restructuring within its mid-Cornwall division in the St Austell area.
In a statement, the company said: “Imerys very much regrets that it is necessary to take these actions and recognises that this is a difficult time for all its employees.
“Every effort will be made to achieve the proposed reductions through voluntary redundancy but compulsory redundancies may also be necessary.’’
Local MP Stephen Gilbert said any job loss was “devastating for the individuals and families concerned”.