A vote on industrial action which could lead to disruption on a major North Sea project gets under way next week.
The Unite trade union is balloting workers employed by Aker Solutions on Equinor’s huge Mariner development, east of Shetland.
Crew on the £4.5billion project downed tools for eight hours in an “unofficial strike” on April 7 in a dispute over pay and working conditions.
They are believed to have declined to work overtime the following day.
Trade union sources suggested a lack of accommodation had led to unfavourable changes in shift patterns.
Union members subsequently rejected a pay offer from Aker Solutions.
They will now vote on whether to strike.
The ballot launches on Monday and will close on July 20.
Unite regional organiser Tommy Campbell said the union has recommended a “yes” vote for strike action and action short of a strike.
Mr Campbell said: “It is disappointing the employer has created a situation where the union has had to go down this road.
“We do not hesitate to ballot our members to deliver what they are entitled to.”
It is understood that the GMB union is also balloting its members.
A spokesman for Aker Solutions said: “We have been notified by Unite the Union and GMB that their members employed by Aker Solutions on the Mariner project will receive a ballot for industrial action.
“This follows the rejection of a revised offer for enhanced terms and conditions for Aker Solutions employees worth up to £8,000 per person on the project. Aker Solutions remains committed to this offer.”
The Mariner project, operated by Equinor, the new name for Statoil, is currently in the hook-up and commissioning phase ahead of first oil later this year.
Mariner is expected to yield 250million barrels of oil over its 30-year production life and create 700 long-term jobs.