Adaptations of Julia Donaldson’s books have long been staples of the Christmas season. Since 2009, the BBC – with its friends at Magic Light Pictures – has wowed audiences with 10 enchanting adaptations of the author’s much-loved children’s picture books, from The Gruffalo through to Zog and Stick Man. And this year is no exception.

Following the same 30-minute format, The Smeds And The Smoos is the latest title in Donaldson and illustrator Axel Scheffler’s best-selling library to receive the festive treatment.

Based on an enchanting outer space adventure, the animation will transport viewers to a faraway planet where Janet (a Smed) and Bill (a Smoo) fall in love, much to the dismay of their warring families.

Following generations of division, the pair have little choice but to elope, meaning the sworn enemies – led by Grandfather Smed and Grandmother Smoo – must overcome their differences to find them.

Janet (voiced by Ashna Rabheru) and Bill (voiced by Daniel Ezra). Picture: PA Photo/BBC/Magic Light Pictures.

Touching on themes of prejudice, the charming tale welcomes Adjoa Andoh, Bill Bailey, Rob Brydon, Daniel Ezra, Sally Hawkins, Ashna Rabheru and Meera Syal to round out the vocal cast.

How did Donaldson and Scheffler first come up with the story?

“It’s so hard to remember,” says Donaldson. “I think Axel had drawn forests, seas, skies, cities – just about everything on the planet – and so I thought I’d take him away from that. I had seen some of his pictures of aliens in Charlie Cook’s Favourite Book, but I’d had the idea a very long time ago and I found some notes I’d written where they were just called ‘the reds and the blues’, originally. It was one of those things that just took a long time to develop in my head.”

How did Scheffler feel about turning his attention to alients?

Grandfather Smed (voiced by Bill Bailey) and Grandmother Smoo (voiced by Adjoa Andoh). Picture: PA Photo/BBC/Magic Light Pictures.

“I did enjoy it. I do enjoy (drawing) made-up creatures because I have more freedom. Well, I never have complete freedom because Julia always tries to keep a bit of control – I knew these had to have hair and shoes and jump about like kangaroos. But obviously Gruffalos and aliens give me a bit more freedom than foxes and squirrels, for instance. So I did enjoy making them up.”

He adds: “I think it lends itself to be animated, and they’ve done such a wonderful job,” says Scheffler. “It’s so rich. It’s so atmospheric. I really love all the different planets, so I think it’s probably a real challenge for the animators, but the result is so wonderful.”

Is there a message behind the narrative?

Donaldson says: “I mean, really, it’s totally pinched from Romeo And Juliet – but with a happier ending. There is so much prejudice in the world, and not just racial prejudice. I remember when we moved to Scotland, there was just so much of ‘us and them.’ Even in sport, it’s fun, but there are some people who really take it to heart and go overboard. So, I hope people learn to be a little bit less prejudiced.”

The Smeds And The Smoos will air on BBC One on Christmas Day.

Christmas Day TV: Julia Donaldson and Axel Scheffler on The Smeds And The Smoos