Around 1,650 North Sea offshore contractors will begin two new rounds of 48-hour strike action in what a trade union said is the biggest walkout in the sector so far.
The workers are striking in an increasingly bitter dispute over jobs, pay and conditions in the offshore sector, Unite said.
The union says BP and Shell recorded “historic profits” of a combined £11.7 billion in the first quarter of 2023.
Offshore workers also walked out in April and May.
Contractors across five companies, including Bilfinger UK Limited, Stork Technical Services and Sparrows Offshore Services will walk out from 6.30am on June 1 until 6.29am on June 3 and then from 6.30am on June 8 until 6.29am on June 10.
Around 600 Bilfinger contractors on the Ithaca, CNRI and Taqa rigs rejected new pay offers, Unite said.
Two hundred Bilfinger contractors working on BP and Repsol assets will also join the strike and around 650 Stork offshore members will join the stoppages in June, along with 200 offshore workers employed by Sparrows.
Unite general secretary Sharon Graham said: “With the support of their union Unite, an army of 1,650 offshore workers are taking the fight to multibillion oil and gas corporations.
“Unfettered corporate profiteering at the expense of our members will not go unchallenged. Unite is determined to deliver better jobs, pay and conditions in the offshore sector, and deliver we will.”
John Boland, Unite’s industrial officer, said: “Unite’s members deserve a much bigger share of the bonanza profits being recorded by oil and gas operators than the real-terms pay cuts currently being offered.
“Around 1,650 members across the companies we are in dispute with remain determined, and fully focused on securing a better deal.
“Whether it is over delivering improved pay, fairer and safer working rotas or holidays, Unite has one simple message for the contractors and operators: we will stand up for our members, we hold you to account, and in the end we will win.”
A spokesperson for Bilfinger UK said: “As an Energy Services Agreement (ESA) signatory, we align with the industry base rates of pay that are agreed annually with the unions.
“This most recent offer of 6% follows a 4% increase that was awarded in January 2023 and combined with the additional increases in June and November 2022 respectively, amount to a greater than inflation pay increase.
“Bilfinger met with Unite immediately following the outcome of the consultative ballot to understand the reasons for rejection and have already concluded a round of meetings with our customers in this regard.
“We remain optimistic that an acceptable solution for all stakeholders can be sought in the near future.
“We respect the right for peaceful and planned strike action and will continue to engage with the unions, our clients and our colleagues to come to a positive resolution.
“Operational safety remains our top priority and we have procedures in place to minimise any potential disruption.”