In one bit of comic nonsense in the musical How To Succeed In Business Without Really Trying, he jumps up and down on a sofa with the agility of a champion gymnast, in a nod to the meltdown moment of a certain box office superstar.

‘We had an intelligent audience in tonight,’ Daniel quipped, when I visited him backstage at the Al Hirschfeld Theatre. ‘They got the Tom Cruise reference.’

‘Sometimes I was dancing for nine hours a day when I wasn’t filming,’ Daniel [said].

‘The thing was to keep practising and practising until you could do it without thinking about it. The aim was to be effortless — or to appear to seem effortless.’

‘I didn’t want the last Harry Potter film to come out and people to say: “So, what does he do now? How does he follow that?” I’m already doing it! I’ve made another film and I’m on Broadway for the second time,’ he [said].

‘I’m doing this for nine months, and I did Equus for five months here and that felt like a long time. I was exhausted after that, so I have to learn to keep my energy levels up with diet and exercise.

‘The rest of the cast work tremendously hard, but I have just two big numbers — Grand Old Ivy and Brotherhood Of Man — and there’s a lot of dancing and singing. They’re exhilarating to do and I love that this is so different from everything else I’ve done. I’m not repeating myself,’ Daniel added.