Just Stop Oil's largest financial backer is a controversial Californian non-profit, the Climate Emergency Fund (CEF), which pays for stunts by environmental groups across the world, including Extinction Rebellion. 

A paper trail of transparency disclosures, seen by The Telegraph, shows that one of the CEF's major supporters is Onward Together, a campaign organisation founded by Mrs Clinton in the aftermath of her 2016 presidential campaign against Donald Trump.

Onward Together gave $300,000 to the CEF in 2021, and a further $200,000 in 2022. The money donated by her group was placed into a fund that was used to pay for Just Stop Oil's protests in the UK.