Construction unions Unite and GMB said workers are angry that the value of their pay has been progressively falling since the pandemic under the National Agreement for Engineering Construction Industry (NAECI).

During Covid, they agreed to a pay freeze even though they provided essential services throughout. In January 2022, they received a two year pay deal of 2.5 per cent for 2022 and again for 2023.

Unite began preparing for formal industrial action proceedings when it became clear the two-year deal put forward for 2024 and 2025 averaging six per cent per year was rejected by 92% of the membership.

Unite general secretary Sharon Graham said: “This offer is completely unacceptable when the industries involved are awash with profits. It does nothing to reverse the shrinking value of these workers’ wages over successive years or that higher pay elsewhere is causing workforce shortages.

“It also ties these workers into gambling on the economy and inflation in 2024 and 2025 when their finances have already been battered by increasingly unpredictable market forces. Unite stands rock solid with our NAECI members – the employers’ must come back with an acceptable offer.”

The ballots for strike action begin opening on 13 September and will close in mid-October, with strike action scheduled to start later that month.

Unite national officer Jason Poulter said: “The anger amongst our membership is such that we are balloting for strike action. The employers must acknowledge that without a better offer, falling recruitment and retention for NAECI roles will only get worse.

“Any disruption caused by potential strikes lies squarely at their door – a much improved offer needs to be put forward if this dispute is not to escalate into widespread industrial action.”

Charlotte Brumpton-Childs, GMB National Officer, said: “Workers covered by NAECI predominantly work on oil refineries and power stations in an industry awash with cash.

“GMB members are not seeing their share of the wealth they are creating.

“They have endured a pay freeze in 2021 and just 2.5 per cent in 2022 and 2023. Their pay is now more than 20 per cent behind where it would be had it kept up with inflation. GMB members have had enough.

“We have written to the employer’s association on multiple occasions trying to secure meeting dates to resolve the issue, our most recent letter offered dates which have been completely ignored. The employers have left the workforce with no choice but to escalate the dispute in an effort to reach resolution.”