Development plans have been announced for an oilfield in the North Sea that could produce almost 70,000 barrels per day at its peak.
Norwegian state-controlled Equinor said it wants to take forward the Rosebank field — which is north-west of the Shetland island archipelago — with the "lowest possible carbon footprint".
Industry body Offshore Energies UK said it would benefit UK energy security and the Scottish economy, but environmental campaigners claim it would be a "total betrayal" of climate goals if the UK Government approves the project.
Uplift, which campaigns for a fossil fuel-free UK, said the Rosebank field would be twice the size of the controversial Cambo development, also north-west of Shetland.
Environmental groups object to Cambo over carbon emissions and the marine damage campaigners say a pipeline would cause.
Uplift also claimed investing in Rosebank would reduce the amount Equinor has to pay under the UK government's windfall tax on energy companies.
Equinor said a final investment decision on Rosebank could happen in 2023, with the next steps for the project including obtaining the necessary consents.
But Uplift director Tessa Khan said: "Rosebank will mean a massive transfer of wealth from the British people to one of the richest petrostates in the world.
"Approving Rosebank would be a total betrayal of both the government's climate goals and the British public who face a severe recession while oil and gas companies make outrageous profits."
Equinor, however, said research shows that over its lifetime Rosebank could generate £24.1 billion of gross value add.
It added that if production starts in 2026, from then to 2030 the field could account for 8 per cent of the UK's total oil production, while natural gas from the site could be the equivalent of the daily average use of a city the size of Aberdeen.
Rosebank at its peak could produce 69,000 barrels of oil a day, OEUK said, along with about 44 million cubic feet of gas per day in its first 10 years.
Equinor senior vice president Arne Gurtner said the company is "committed to net-zero by 2050 and is ready to invest to bring energy security while also transitioning to lower-carbon energy sources over the coming years".
"Here in the UK, we are building the world's largest wind farm, Dogger Bank, and are planning some of the largest hydrogen and CCS [carbon capture and storage] projects in the world," Mr Gurtner said.
"That said, for the next few decades oil and gas will continue to play a vital role alongside these low-carbon systems.
"Therefore, while we still need oil and gas, we aim to develop and operate projects such as Rosebank with the lowest possible carbon footprint while bringing the maximum value to society in the shape of UK investment, local jobs and energy security."
Greenpeace to fight Rosebank
But Philip Evans of Greenpeace UK said: "This is what happens when the government helps out oil companies with cushy tax breaks.
"If Rosebank goes ahead, it will do nothing to help drivers or households with rising costs, because the oil doesn't belong to the UK and goes to a global market."
Greenpeace is already bringing a legal challenge over the planned Jackdaw development in the North Sea.
"We will fight Rosebank every step of the way, and urge the government to crack on with quick, cheap solutions that will actually help in the cost-of-living crisis and the climate emergency — renewables, home insulation and heat pumps," Mr Evans said.
Scottish Green MSP Mark Ruskell said it is the "height of irresponsibility to be developing new oil and gas fields in the face of the climate emergency".
"Scotland has massive renewable energy potential," he said.
"The UK government's failure to invest in this, and instead double-down on oil and gas, is a sad inditement of its priorities which focus on short-term profits over the wellbeing of future generations."