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.

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.

But what do duo Donaldson and Scheffler think of their latest special? We sit down with them to find out.

 

HOW DID YOU FIRST COME UP WITH THIS STORY?

J: It's so hard to remember. 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 YOU FEEL ABOUT TURNING YOUR ATTENTION TO ALIENS, AXEL?

A: 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.

 

WAS IT FUN TO INVENT WHOLE NEW WORLDS IN SPACE?

A: Yeah, that was really lovely to do the other planets. That was the most enjoyable thing. But I did lots of sketches for the aliens and I could just do whatever I wanted, stilty eyes and everything. It was a joint decision as to how Janet and Bill ended up looking.

J: It was also quite good fun making up the names of the planets, especially since they could fit into the scansion on the rhymes. Say if I knew I needed a one-syllable planet like Glurch or Grimbletosh, I could fit them in. But it was harder than you think. I wrote those bits on a train.

 

HOW DID THIS COME TO BE THE NEXT FESTIVE SPECIAL?

A: I think it lends itself to be animated, and they've done such a wonderful job. 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.

J: One of the things I really liked was, in my mind, when I wrote it, I very much imagined the interior of the rocket. But in the picture book, it's hard to fit it all in, so it was lovely that that could be developed. They could obviously do a lot more of that on the film.

 

IS THERE A MESSAGE BEHIND THE NARRATIVE?

J: 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.

A: I agree with that. But also, I worked on it when this country decided to go the way of division at the time of Brexit. So I think it's a very strong message for unity and against prejudice and overcoming divisions to work together.

 

WHAT WAS YOUR REACTION WHEN YOU FIRST SAW THE FINISHED PRODUCT?

A: It's just wonderful; there's new things to discover each time. For me, it's always amazing to see what happens between the pictures and the film because obviously I can't do everything in the book. So to see the characters from different angles or to see what happens in between, when you pack out the pages, is always wonderful because the narrative is so much richer.

J: Yeah, it is all in the details. I already get this thrill when Axel puts extra little details into the pictures and then in the film... But talking of reactions, I get a lot of letters from parents (after reading the books) saying, 'My child has been learning punctuation at school and they pointed out that their teacher said you should never have a comma before the word 'and'. That's strange, isn't it?'. I'm sure it's the parents editing.

 

WOULD EITHER OF YOU LIKE TO ADD YOUR OWN VOICES TO A FUTURE ADAPTATION?

J: Well, I'm not sure about the films, but this is a good opportunity to boast about something else. As well as this, the screen version of my Princess Mirror-Belle stories (for slightly older children) is out, and I'm in one of the episodes as a children's writer. So yeah, I have a cameo role and that was great fun. So yes, I would if you'd like to cast me.

The Smeds And The Smoos will air on BBC One on Christmas Day, 2.30pm.