More than 400 Imerys staff - predominantly based at clay mines in Cornwall - are to strike over pay, according to their union. 

Unite said that in 2022 the 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, over increasing the 2023 pay award, would continue during the spring.

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

The union claims that since then 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.

This has been disputed by Imerys, which said it had actually offered an eight per cent year-on-year pay increase - six per cent from January 2023 and an additional two per cent offered from April 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.”

In February 2023 French company Imerys published its 2022 financial report, which recorded a full year revenue of €4,282 million (£3,654 million) and a net income from continuing operations of €284 million (£242 million).

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 more than 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 told the Packet: “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 per cent year-on-year pay increase. Six per cent has already been paid from January 2023 and an additional two per cent has been offered from April 2023, not six per cent overall as stated by Unite."