Campaigners say the controversy surrounding the new television adaptation has already led to opposition from within the entertainment industry. They point to comments from Canadian director Ally Pankiw, known for her work on Black Mirror, who said she had turned down an opportunity to work on the series, stating: “It is simply this easy to say no to funding transphobia.”

The petition places particular pressure on Khan, who has previously described himself as an ally to the trans community and repeatedly said that trans rights are human rights. Supporters argue that allowing a Harry Potter-themed display in one of London’s most prominent shopping destinations would be at odds with those commitments.

A spokesperson for Good Law Project said: “How can Mayor Khan tell trans Londoners that ‘this city is yours too’, whilst allowing a Christmas lights display to go ahead that will help fund anti-trans rights groups? The mayor must back up his words with action.”