Ministers met with Onward, accused of being “a fossil fuel dinosaur in new clothing”, more than any other think tank last year.

BP sees sponsored content as a crucial tool to reach “Washington, DC, elites,” according to subpoenaed memos.

After donating £50,000 to a Conservative faction in December, the Legatum Institute has now hired Lynton Crosby’s influential CT Group.

Despite calls to stop representing polluters, Edelman will continue to promote one of the world’s biggest producers of oil and gas.