Shell pulls out of a U.K. oil field targeted by climate activists.

Royal Dutch Shell said Thursday that it had decided not to invest in a British oil development off the coast of Scotland that has become a test of the government’s environmental credentials.

The field, known as Cambo, is in deep water northwest of the Shetland Islands. It is seen as a bellwether for the future of Britain’s declining but still large North Sea oil industry.

The British government is considering whether to approve the project, which environmental groups and some politicians have said should be rejected because it would produce carbon dioxide emissions responsible for climate change.

Shell, which owns 30 percent of Cambo, said it had “concluded the economic case for investment in this project is not strong enough at this time.”

The company also said there was “potential for delays,” apparently referring to the possibility that the drilling would draw protests from environmental groups and possibly legal actions trying to stop it. Shell said recently that it planned to move its headquarters from the Netherlands to Britain.

Shell’s decision to decline to invest in developing Cambo is a serious blow to the project. Siccar Point Energy, a private equity-backed firm that is Cambo’s main owner and developer, said that while “disappointed” by Shell’s decision, it remained “confident about the qualities” of the project, saying it would create 1,000 jobs.

Siccar Point has said that it plans to invest $2.6 billion in Cambo and that it has already spent $190 million in the four years since it acquired the rights to the field, which was discovered in 2002.

The oil industry argues that as long as Britain consumes more oil and natural gas than it produces, it is preferable for those fuels to come from the North Sea, where emissions regulations can be set, instead of from places with potentially fewer controls.

The environmental group Greenpeace UK said letting Cambo go ahead “would be a disaster for our climate and would leave the U.K. consumer vulnerable to volatile fossil fuel markets.”