Helena Rees-Mogg is flustered to find me already in her sitting room at their Westminster town house when she arrives back from the school run, having popped in for a quick blow dry on the way home.

In response, his wife Helena Rees-Mogg, 47, asks: “But what if you’re the one in the Bangladeshi factory with no air conditioning?” Sir Jacob responds: “You starve otherwise. So which do ...