Unite’s NAECI members carry out essential repair and maintenance at oil refineries, power stations and pharmaceutical and petrochemical plants.

Workers at Drax, Sellafield, Stanlow, Pembroke, Grangemouth, Teesside Sabic TIP and Runcorn Project Summer Vynova, who operate under the National Agreement for the Engineering Construction Industry (NAECI), last week voted by 86% to reject a two-year pay offer of 10% for 2024 and 5% for 2025.

The offer, from the employers who negotiate the NAECI agreement with unions, does not go far enough to restore years of falling wages for engineering construction workers, Unite said.

Unite general secretary Sharon Graham said: “NAECI workers have seen their pay fall further and further behind in real terms as a result of the pandemic and the cost of living crisis. Meanwhile, most NAECI employers have benefited from huge profits generated from rocketing energy and fuel prices. NAECI contractors and clients can fully afford to put forward a better offer and this is what must happen.”

Unite is now preparing to ballot even more workers at other sites across the country to join any industrial action.

Unite national officer Jason Poulter said: “There is a limited window of opportunity for NAECI contractors and clients to avoid widespread industrial unrest.

“They have the money to ensure that our members’ rates are restored to their previous value. Their latest offer was inadequate and was overwhelmingly rejected by our members. They need to get back into negotiations and work with us to find an acceptable offer.”