North Sea oil workers are to stage a series of offshore strikes in a dispute over pay and conditions with French energy giant Total.
The Unite union said the move - which will affect three Total-operated platforms - followed a vote in favour of industrial action last month.
Workers on the Alwyn, Dunbar and Elgin platforms will walk out on five days between 23 July and 20 August.
There will also be a continuous ban on overtime from 23 July.
Total said it hoped for a negotiated solution.
Unite said the dispute concerned the company's wage review and plans to increase workers' offshore working time.
Regional officer Wullie Wallace said: "The overwhelming vote in favour of strike action demonstrates the fury at Total's proposals to impose changes to the working practices and conditions on its three platforms.
"There remains a closing window of opportunity for Total to behave responsibly and engage with Unite to revise its current offer.
"However, if Total does not wish to negotiate, then they will be left in no uncertain terms of the strength of feeling of Unite members which will lead to widespread disruption of the company's operations."
Jean-Luc Guiziou, managing director of Total E&P UK, said: "Our workforce at the Shetland Gas Plant and on the Elgin, Alwyn and Dunbar platforms do a very good job and we will do our best to work towards a resolution of this dispute.
"I know from talking to our workforce that we can find a negotiated solution. We have started a structured process of meetings and workshops that will hopefully allow us to reach a consensus."
He added: "By moving to a 3/3 rota, we'll be in a much stronger place to grow our business and increase operational excellence.
"Our objective is to seek a rota system that both enhances overall safety and is the most efficient - in this way we will ensure the long-term sustainability of our business in the North Sea.
"I also believe that we will only move forward together, so I look forward to a constructive dialogue with our offshore staff and their representatives."