The strike – on 26 July 2016 – will be the first industrial action of its kind in the offshore energy industry in nearly 30 years.
The RMT and Unite unions said their members who work for Wood Group – which is contracted to provide offshore services to Shell – have organised the action over the company’s plans for “swingeing” pay cuts.
The unions said next week’s strike was likely to be followed by several further stoppages.
The strike is likely to “severely disrupt” operations on seven Shell platforms in the North Sea – Shearwater, Gannet, Nelson, Curlew, Brent Alpha, Brent Bravo and Brent Charlie.
Paul Goodfellow, Shell UK and Ireland Upstream Vice-President, said: “We are disappointed by this development and hope that Wood Group’s employees and management will continue in their discussions in an effort to resolve their issues.
“Our priority is to ensure that safety will not be compromised during any industrial action.”
Unite regional officer John Boland said: “Strike action by our members is not a decision they take lightly, but they have been pushed to the limit by an employer unwilling to rethink proposals to slash their pay and allowances.
“This is the third series of redundancies, and cuts to our members’ wages and terms and conditions in the last two years.
“Our members have already made sacrifices and are experiencing the effects of the imposition of a three-week working cycle which means more time offshore and less time with their families, for the same salary.”
A spokeswoman for Wood Group said: “We are extremely disappointed that they have chosen to take industrial action, but we respect their right to do so.
“We continue to engage proactively and openly with our employees and the unions with a focus on reaching a resolution. Safeguarding these jobs in the North Sea now and in the future has always been, and remains, our priority.”