More that 1,300 offshore workers are to stage a 48-hour strike in a dispute over pay.
Unite warned that dozens of oil and gas platforms will be brought to a "standstill" by the walkout from April 24.
"There's no question that contractors and operators can easily afford to give Unite members a decent pay rise.
"The scale of corporate greed in the offshore sector has to be challenged.
"1,350 offshore workers will now take part in an unprecedented tsunami of industrial action over 48 hours with hundreds more set to join them.
"Unite will support all our members every step of the way in this fight for better jobs, pay and conditions."
Workers taking industrial action include electrical, production and mechanical technicians in addition to deck crew, scaffolders crane operators, pipefitters, platers and riggers.
John Boland, Unite industrial officer, added: "Unite has received an emphatic mandate in support of strike action.
"It is historic and it will be the biggest offshore stoppage in a generation.
"Unite's members are determined to get their fair share and to establish a better working environment.
"This is not exclusively about pay but also working rotas, holidays, and offshore safety.
"The workforce has been taken for granted for years but now their value will be acutely felt when strike action will bring dozens of platforms to a standstill."
By City AM
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