Talks have resumed over a china clay company's plans to cut hundreds of jobs in the South West.
Some of the Cornwall operations will be moved to Brazil
Union leaders say they have made minimal progress in reducing 600 planned job cuts in Devon and Cornwall at pits owned by Imerys.
Negotiations by the Transport and General Workers Union and Amicus ended in August with 11 jobs saved.
French firm Imerys said the changes were necessary to protect the business's future.
Unions are to call for the firm to reduce the number of job losses and for enhanced redundancy pay-offs.
The union is set to call a mass meeting of members to ask the workforce what action may be taken.
The company, which employs about 2,000 staff in the region and is Cornwall's largest private employer, has blamed high energy prices, a weak dollar and strong overseas competition for significant losses.
The Blackpool Pit, near Trewoon in Cornwall, will close at the end of next year and some of the current operations will be moved to Brazil.
Imerys said no conclusions had been reached yet about packages and cuts.
A spokesman said: "We've looked at a number of options ourselves, we've made a number of proposals and we're discussing through all of those as we carry on the process."