“If you just play the characters completely neutrally … hopefully that’s not going to be controversial in any way and you’ve just got a good mix of characters, which I think is important.”

“Neutral” characters doesn’t mean Walliams is afraid of challenging readers. He feels strongly that his books should be more than just vehicles for jokes. Behind the comedic prose they have tackled issues such as dementia, grief, homelessness. It helps create stronger dramatic tension but more than that “I’m acknowledging the real world”, Walliams says.

“If you want to take the kids on a journey, you want to take them on an emotional journey. It’s going to resonate with them more … you want [a book] to make you really care about what happens. It’s all fun and games to have lots of silly things or silly characters, funny clothes, but why are you going to read the next page? It has to be because you care about the people.”

Another way to improve un-diverse texts is in a new production. In 2016’s The Midnight Gang, one of Walliams’ best-selling and loved books, each of the five children in the titular gang is illustrated pink-faced (the hero is a boy, two of the five are girls). But by the time the BBC’s 2018 production hit screens, to critical and viewer acclaim, two of the five were also black.

Walliams is delighted when this happens. “It shouldn’t matter at all,” he says. “I mean, there’s no reason why Charlie in Charlie and the Chocolate Factory can’t be black. The colour of his skin is never mentioned and it doesn’t matter.

“I think also people are really receptive to it. In the theatre you go to see Warhorse and you’re meant to believe, you do believe that this puppet of this horse is real. And so the idea that you couldn’t think two people were related when one was white and one was black – it’s like you’re already suspending the disbelief.”

Walliams is on Zoom to help publicise a stage production of The Midnight Gang which has been touring Australia and passes through Melbourne this weekend.

He believes the “shared experience” of theatre will keep it alive, in the face of ever-growing competition from the endless streams of online content. Theatre, he says “makes it very real and also can make it funnier”. He loves the euphoria and magic there, which draw audiences to their feet applauding and leave memories that last years after TV and movies fade.

“It’s just telling stories, and as long as there’s new stories to tell it will live on,” Walliams says. “At the theatre I always have a look round at who’s there. It’s often older people. But if you put on a show that will appeal to younger people … you’ll notice it’s not lots of old white people [watching]. It’s lots of young people. People will come to a show that they feel is relevant to them.”