Martin Lewis, photographed for the New Statesman by Charlie Forgham-Bailey

Every morning, Martin Lewis reads his emails and the papers while kicking off the first 7,000 of his daily 23,000 steps on his cross-trainer. And every morning, he makes sure to check one thing in particular: the UK natural gas price. He shows me this on his phone screen when we meet, two weeks before the Budget. It’s £2.14 a therm. We watch as the number, atop a jagged Alpine peak, blinks upwards.

“I’m in hyper mode,” Lewis apologised, having rushed back from recording his twice-weekly podcast, which he fits in alongside his BBC 5 Live radio phone-in, constantly updating his nine million social media followers, breakfast TV and a frenetic live evening show.…