More than 1,300 offshore workers are to stage a 48-hour walkout in a dispute over pay.
Unite said dozens of oil and gas platforms could be brought to a “standstill” by the strike across five companies.
Last month, the union warned of a “tsunami” of industrial unrest among offshore workers over pay and conditions.
“Oil and gas companies in the offshore sector are enjoying record windfall profits,” Unite general secretary Sharon Graham said.
“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.”
The strike action, involving electrical, production and mechanical technicians in addition to deck crew, scaffolders crane operators, pipefitters, platers and riggers, is set to start on April 24.
In March, Offshore Energies UK’s (OEUK), the industry’s trade association, published a report claiming falling investment due to windfall taxes, political uncertainty and inflation was jeopardising the prosperity of British oil and gas.
On Wednesday, major North Sea oil firm Harbour Energy confirmed it is set to axe 350 onshore jobs in Aberdeen, as a result of the windfall tax.
STV News has contacted the employers for comment.
A spokesperson for Sparrows Group, which provides services across more than 20 oil and gas platforms to operators including Shell, Apache and Harbour Energy, said: “We are disappointed that our employees working for various clients are planning to commence with industrial action.
“We have previously increased rates in line with industry standards and propose to continue with that alignment.
“We are working with our clients to deliver our normal operational services during these periods of action, while ensuring the ongoing safety of personnel and operations.”
A Petrofac spokesperson: “We are committed to resolving this dispute through ongoing constructive dialogue with the union and our clients.
“Ensuring no increased risk to the safety of our personnel or the environment during industrial action remains a priority.”