Sir Paul showcased the book to schoolchildren in 2005
Sir Paul McCartney's children's book about the adventures of a squirrel is to be adapted for the big screen.
The musician will also write new songs for the animated version of High in the Clouds, according to Hollywood trade newspaper Variety.
Rob Minkoff, whose credits include The Lion King and the Stuart Little films, will direct the release.
The book, published in 2005, tells the story of Wirral The Squirrel's search for an animal sanctuary.
It was co-written by Philip Ardagh and illustrated by Geoff Dunbar.
Michael Lynne, part of the team bringing the project to life, said: "Paul said he would commit a score of original songs as part of it."
He added that the story had convinced him and his partners to make an animated feature for the first time in their career.
Lynne's previous production credits include the blockbuster Lord Of The Rings trilogy.
This will be Sir Paul's biggest involvement in a major animation since The Beatles' Yellow Submarine in 1968, when he was one of the main stars of the film.
The songwriter's 1984 hit We All Stand Together was also taken from an animated feature, Rupert and The Frog Song.
Wirral the Squirrel, described as a "cheeky Scouse nut-muncher", made his animation debut in a video accompanying Sir Paul's 2004 song Tropical Island Hum.
The star said at the time that an interest in cartoons brought out some of his "child-like quality".