Construction workers on the ยฃ20 billion Hinkley Point nuclear power station are to be balloted for strikes in a long-running dispute over pay and bonuses.
Hundreds of jobs are at risk across six member companies of the Caterers Offshore Trade Association (COTA).
The estimated figure was revealed as another union said it would ballot members over whether to take industrial action over a pay dispute.
In a letter seen by Energy Voice the chairman of COTA and chief executive of Entier, one of the member companies, warns around 500 positions are being consulted on.