A Greenpeace challenge to the UK Government over a decision to allow BP to drill for oil in the North Sea is “largely procedural and opportunistic”, a court has heard.

Roddy Dunlop QC, representing the UK Government, said the indirect effects of eventual burning of oil and gas from the Vorlich field were not “material considerations” because that is taken into consideration as part of the net UK carbon account.

Greenpeace is taking legal action against the UK Government, challenging the decision to grant BP a permit to drill for oil in the Vorlich field in 2018.

In a hearing at the Court of Session, Scotland’s highest civil court, it is calling for the decision to be overturned, and for BP’s permit to be revoked.

Greenpeace said it is the first time an offshore oil permit has ever been challenged in court and that if it wins, the case could have huge ramifications for how the UK Government makes future oil permit decisions.

The court previously heard from Ruth Crawford QC, representing Greenpeace, who said that when the application for drilling consent was first submitted, the environmental organisation would have wanted to make representations on a number of issues including the “failure to assess climate change and the impact of greenhouse gas emissions”.

Mr Dunlop, dean of the Faculty of Advocates, told the court on Thursday: “The overall direct emissions from the development of the Vorlich field forms part of the Government’s clean growth strategy that includes the setting of carbon budgets for the United Kingdom.

“The direct emissions from producing the oil and the gas, that’s able to be quantified and it’s considered and taken into account within the UK’s annual statement of emissions.

“But emissions that arise from the eventual combustion of oil or gas to be extracted from the Vorlich field, that’s captured in an inventory and it forms part of the net UK carbon account, something that is a matter of political judgment.

“The wider indirect effects of that combustion are not material considerations.”

He added: “The challenges advanced by Greenpeace are largely procedural and opportunistic.”

Ms Crawford said she does not accept the term “procedural” should be used in a pejorative sense, as she said it appears to be.

She said: “The appellant (Greenpeace) makes no apology in asking this court to ensure that the Secretary of State complies with the law, as represented in the regulations, to ensure that an effective EIA (environmental impact assessment) process is carried out and that there is proper public participation in important developments such as the Vorlich oil field.”

Production from the Vorlich development started in November 2020 after BP was granted approval by the Oil and Gas Authority (OGA) in September 2018.

Jim Cormack, representing BP and Ithaca, said the challenge was “highly significant” as if it were overturned, production from the field would have to stop at least until a substitute consent could be obtained.

He said the works for which consent was granted have been implemented by BP and Ithaca at a cost of around £230 million and the project is fully operational and in the production phase.

Ross McClelland, representing the OGA, also told the court that its position was that operations would have to stop.

The court heard that the OGA cannot grant its consent for a drilling project unless the Secretary of State agrees having done an environmental impact assessment.

Mr Dunlop urged the judges, who are hearing the case virtually, not to quash or reduce the consent.

He said: “The first respondent (the UK Government) is concerned that there could be health and safety issues associated with mothballing the Vorlich field and that would be the consequence of the order if the consent were to be reduced, then the field can’t be operated lawfully and it would have to be a shutdown with serious consequences.

“To require that to happen in the event of one or more of the technical breaches advanced by Greenpeace being established would be wholly disproportionate, hugely expensive and potentially unsafe.”

Lord President Lord Carloway, Lord Menzies and Lord Pentland, who are hearing the case, deferred judgment and said they would issue a decision “as soon as we can”.