UK energy secretary leaning towards rejecting the giant Rosebank oilfield, in a possible victory for climate campaigners

The UK energy secretary, Miatta Fahnbulleh, is leaning towards rejecting the giant Rosebank oilfield, it is understood, in what would be a blow for the North Sea energy industry but a major victory for climate campaigners.

Officials say the energy secretary is minded to refuse approval for the field, which would be one of the biggest in the North Sea. Fahnbulleh approved the smaller Jackdaw gasfield on Wednesday, prompting protest from some in the green movement.

But she has said the rationale behind Jackdaw did not apply to Rosebank, saying the UK would rely on gas as it made the transition to net zero and that it would be better to take it from relatively low-carbon sources in the North Sea than importing it.

'One is a gasfield that caters for the domestic market, while the other is an oilfield that is mainly for export,' she said. 'It is right that we judge each application in its own right, and it is absolutely critical that the decision is consistent with our climate obligations, our carbon budgets and the end destination we need to get to with the energy transition.'

Officials say Fahnbulleh has not yet taken a final decision on Rosebank, but a ruling is expected later this year. The field would emit around seven times the carbon of Jackdaw, and Fahnbulleh is understood to believe it would do less for UK energy security given most of the oil would be exported.

On a visit to Aberdeen to announce the Jackdaw decision, Fahnbulleh said she had been satisfied that Jackdaw, which is due to begin producing gas within weeks and will add an estimated 36m tonnes of carbon emissions, would not violate the UK's climate commitments.

'As we make the transition we are going to need gas,' she said. 'At a point when we have got conflict in the Middle East that is triggering an energy crisis, energy security is vital, and homegrown energy is key.' She admitted, however, that it would not help achieve the government's main energy target of bringing down bills, saying: 'This is not about bills.'

The UN Environment Programme has recommended global carbon emissions be cut by nearly a fifth in the next four years, and by close to half within a decade, to avoid overshooting climate targets by a disastrous margin.

Fahnbulleh has promised that future revenues from the North Sea would be spent on green energy projects through a new energy wealth fund. The fund will be given £2bn in the budget, she said, some of which would be reallocated from other parts of her department's budget. However, she could not say exactly which tax revenues would be given to the new fund, or how much that might generate; the chancellor will make those details clear in the budget, she said.

While Labour's 2024 election manifesto committed to a ban on new drilling licences in the North Sea, the companies behind the Jackdaw and Rosebank projects have sought approval for existing licences, and they resubmitted their applications for environmental approval earlier this year. The government said the Jackdaw field will start supplying gas to homes and businesses from the end of the month after the scheme was approved.

Asked how confident he was that the Rosebank field would be approved, Neil McCulloch, the chief executive of Adura, one of the companies behind the plans, told the Press Association that they were very confident now. He said a decision-making process had been shown to work, but examining the two fields separately was a matter for the secretary of state and her team, adding that they believed they had argued as good a case for Rosebank as for Jackdaw — it is a bigger field, will last longer, and he was sure she would take its jobs and economic impact into account.

The Jackdaw announcement could boost Labour's position in north-east Scotland, where much of the industry is based and unions have campaigned heavily for the permits. But it is likely to cause angst among some Labour MPs, especially those facing a challenge from the Green party. A poll by Savanta for the climate group E3G shows that nearly a third of voters say they would be less likely to vote Labour if it gave the go-ahead for more North Sea oil drilling — including almost exactly a third of those who voted Labour at the last election, and about half of 18- to 24-year-olds.