Conservatives, behold what could be your next leader dangling helplessly from a zip line.
The mayor was left hanging in mid-air at an event in Victoria Park. According to ITV News Boris had to be pulled back down to earth by teams on the ground.
Boris, the first person to use the wire, was heard shouting: "Get me a rope, get me a rope ok?"
As chuckling onlookers snapped pictures, he was heard to say: "I think they need to test this on somebody going a bit faster".
Rumours that Mitt Romney's presidential campaign tampered with the mayor's equipment as retribution for him publicly mocking him in front of 60,000 Londoners have yet to be proven.
Of course, fingers may also be pointed at David Cameron, who must be getting increasingly irritated at predictions that Boris wants his job.
Inevitably having heard the news, the internet went to work, Photoshopping the dangling mayor into various locations.