To watch a candidate register his own political death in real time is both highly unusual and deeply uncomfortable. Little more than an hour earlier, Rory Stewart had roared into the BBC1 live leadership debate as the bookies’ surprise second favourite to become our next prime minister. He emerges to meet me looking ashen, shell-shocked, reeling from the “disastrous” debate.

“I don’t know at all how to do this,” he admits quietly. Without a live audience in the studio, everything had gone wrong. “The type of communication that I bring just didn’t work at all — and the [other candidates’] stuff that I thought was fake or inauthentic suddenly sort of worked.” Lost in thought, he picks at a sandwich, his words punctuated by agonising