At the Court of Session, Equinor, Ithaca Energy, Shell and the government all accept that the Supreme Court ruling means the licences for Rosebank and Jackdaw were granted unlawfully.

But the companies say they provided full and accurate environmental assessments in good faith under the law as it was understood at the time; they were explicitly told by the government not to assess downstream emissions; and they should not be “punished” for a Supreme Court decision which they say they could not have foreseen.

On that basis they want the judge, Lord Ericht, to allow them to continue working towards starting production in the fields.

Shell’s advocate, Christine O’Neill KC, told the court that production at Jackdaw was expected to run from 2026 to around 2034.

The company, she said, was investing £1.1bn in the project, providing jobs for “at least 1,000 people” between 2023 and 2025.

If it were stopped, she added, it would mean that “more than three quarters of a billion pounds that’s already been spent will have been wasted.”

Even a 12 month suspension, added Ms O’Neill, would be likely to cost Shell “at least £200m.”