The author joked how Camilla would often tell him to “get on with it” and if he had an issue in his life she would tell him to “not moan about it” if he had a problem. Speaking on The Chris Evans Breakfast Show on Virgin Radio UK this week, Tom, 49, also praised his mother Camilla’s work ethic.

Tom replied: “I don’t think it’s really changed – you’ve seen her a hundred times – she hasn’t changed. I think her job description has perhaps changed. Her job has massively changed. Most people are retiring at her age and she’s going full tilt. She’s a grafter. She was a great mother. When you have to do stuff, she says ‘Just get on with it, do it, don’t talk about it, don’t moan about it.'”

Tom, whose latest cookbook, Cooking and the Crown, details the history of food within the royal family – from the reign of Queen Victoria beginning in 1837 and Edward VII at the turn of the century, to Charles and Camilla, also discussed the King and Queen’s love of mushrooms. When Evans said he wished he knew “more about foraging them”, Tom replied: “Wild mushrooms are just wonderful.

“I don’t know enough. I only know three kinds of mushrooms… there are a couple of serious foragers, actually, and I’m not just plugging it here, my mother and the King are good mushroomers, mycologists.

“They really know their stuff. In Scotland, I go with my mother and she knows her stuff about mushrooms but I wouldn’t… you pick the wrong one, you’re dead.” Last week the writer paid tribute to his mum by labelling her ‘tough’ for being by the King’s side this year following his health problems.

Buckingham Palace announced in February that Charles was diagnosed with an undisclosed form of cancer, but Parker Bowles confirmed his “doctor says the treatment is going well”. He also praised the King for being a recycling champion who “appalls waste”.