Hundreds of clay mine workers predominantly based in the St Austell area are set to strike over pay. 

More than 400 Imerys staff are to take industrial action Unite, the UK’s leading union, has confirmed.

In 2022, Imerys workforce agreed to an initial six per cent pay rise from January 2023.

The good faith agreement was on the condition that negotiations with Unite on increasing the 2023 pay award would continue during the spring.

This was because the initial rise was a significant real terms wage cut, as RPI inflation at the time stood at 13.4 per cent.

Since then, however, the company has refused to put forward an acceptable offer and is insisting workers will only receive backpay from April 2023 rather than January 2023.

Unite general secretary Sharon Graham said: “Our members are sick and tired of Imerys acting in bad faith over pay.

“Unite will not accept attacks on pay from Imerys, which can more than afford a reasonable rise for the whole of 2023.

"Our members have Unite’s absolute backing for strike action and will receive the union’s full support.”

Imerys had a turnover £225 million and gross profits of £48 million in 2022. It operates open pit clay mines and produces kaolin, ball clay, calcium carbonate and calcium aluminates for numerous industries.

The company is one of Cornwall’s largest employers and the dispute involves over a third of Imerys’ employees, who undertake a range of roles.

Dates for strike action, which will result in significant disruption to the company’s operations, will be announced in the coming days.

Unite regional officer Dave Smith said: “There is still time for strike action to be avoided but for that to happen, Imerys needs to put forward an offer our members can accept.”

A spokesperson for Imerys in the UK said: “We would like to thank colleagues across the southwest for their patience and hard work at this unsettling time.

"Whilst acknowledging and respecting the results of the ballot by Unite - in which only 180 out of approximately 800 colleagues impacted actually voted for strike action - we hope to find a resolution so we can move forward and focus on returning to growth in 2024.

"Finally, we would like to clarify that we have offered an eight percent year-on-year pay increase.

"Six percent has already been paid from January 2023 and an additional two percent has been offered from April 2023, not six percent overall as stated by Unite."