Robert Jenrick's use of weight loss jabs signals his true ambition

You couldn’t get a better illustration of the gulf between the political cultures in the US and the UK than the muscle-flaunting fitness challenge issued this week by Pete Hegseth and Robert F Kennedy Jr.

The Defence and Health Secretaries competed to finish 100 push-ups and 50 pull-ups in under ten minutes as part of a campaign to make young Americans “fit, not fat”. In Britain, we tend to settle for photos of exhausted looking leaders trying to puff their way along a “jog” in which their accompanying security detail doesn’t even break into a sweat.

Boris Johnson used to make a point whenever the press were camped outside his front door of going for an implausible run dressed in even more improbable kit, though he would sometimes just loop around the back of his house, rather than actua