The action could include up to 3,000 workers at Stanlow, Fawley, Valero, Grangemouth and Mossmorran Oil Refineries, as well as at the Sellafield nuclear facility.

Further strike votes are also expected at Drax and Hartlepool nuclear power station in the coming days.

The workers, who are covered by the National Agreement for the Engineering Construction Industry (NAECI), voted to turn down a pay deal of 8.5% for 2024 and 3.5 per cent for 2025.

The ballots proceeded despite last minute attempt by contractors to better this offer to a 10% rate rise in January, followed by a 5% rise in 2025.

The Blue Book agreement as it is also known covers up to 8,000 workers in the sector, with around half working on mainstream refinery and power station sites around the country.

More than 50 GMB and Unite reps from across the industry will now meet to discuss next steps.

Charlotte Brumpton-Childs, GMB National Officer, said: “’Our members’ pay has fallen over 20 per cent behind inflation.

“The employers have forced our members into a position where they are taking part in industrial action ballots of this scale for the first time in their careers.

“The message from the workforce is loud and clear: value their work.”