Celine Dion will lead the voice cast of Sir Paul McCartney's 3D animated film

The project is being directed by Toby Genkel, and he'll oversee a star-studded cast that also includes Idris Elba, Lionel Richie, Jimmy Fallon, Pom Klementieff, Alain Chabat, Clemence Poesy and Sir Ringo Starr, McCartney's former Beatles bandmate.

'High in the Clouds' will feature original songs written and composed by McCartney, who is also serving as a producer on the project.

The film adaptation is being produced by Gaumont Animation, while 88 Pictures is overseeing the animation elements of the movie.

The original adventure novel centres on a teenage squirrel called Wirral, who embarks on a journey to set music free.

McCartney wrote the book with the help of Philip Ardagh, the children's author who has written more than 100 books during his career.

'High in the Clouds' was McCartney's first children's book, but he's subsequently written more, including 'Hey Grandude!' and 'Grandude's Green Submarine'.

The Beatles icon previously explained how his grandchildren inspired 'Hey Grandude!'.

Speaking to the BBC, he shared: "One of my grandkids - who used to call me 'Grandad' - just happened one day to say 'Grandude' and it kind of stuck. So the other kids started calling me 'Grandude'."

Despite this, McCartney's grandchildren are barely aware of his own fame and success.

The singer explained: "I sometimes will say to the audience, 'My grandkids are here'. It's crazy for them. They've got this grandad up on stage rocking out."

McCartney also stressed that he's not the specific inspiration behind the Grandude character.

The chart-topping star shared: "Grandude isn't supposed to be me. Because he's magic and I'm not."

McCartney always enjoyed reading stories to his own children. And the award-winning musician believes there's still a place for traditional storytelling.

The 'Hey Jude' hitmaker said: "I like that - at the end of the day - sealing the day by reading to the kids. It's something I've always liked doing. And it's very satisfying when you see them nod off."