Michael Morpurgo novel Kensuke's Kingdom is set to become an animated movie from the makers of Ethel and Ernest and We're Going on a Bear Hunt.

Lupus Films previously brought Michael Rosen's We're Going on a Bear Hunt and Raymond Briggs' Ethel and Ernest to the small screen, and now they are turning Morpurgo's 1999 award-winning children's book into a feature film. 

Speaking at the BFI & Radio Times Television Festival in London alongside The Tiger Who Came to Tea author Judith Kerr, Morpurgo revealed: "We are going to make a full-length animated film."

The script is by fellow children's author Frank Cottrell-Boyce. But though the movie has been a long time in the making, so far it exists only as a 55-second trailer.

The clip reveals a small boy and his dog who fall overboard during their family's round-the-world sailing trip. Stranded on an island in the Pacific, they think they are all alone - but the island is actually the territory of Kensuke, an old Japanese soldier. 

Author Michael Morpurgo

"They've started now, and they took it to a festival in Bordeaux, and now the search is on for the money," War Horse author Morpurgo said.

"I think it will be made in about two years' time. The people who are making it are called Lupus Films, who are the people who made that wonderful production of Raymond Briggs' Ethel and Ernest at Christmas. And also the other one, that wonderful Michael Rosen book We're Going on a Bear Hunt. If Michael Rosen can do it, I can do it!"

The collaboration between Cottrell-Boyce and Morpurgo dates back to a conversation many years ago, according to Sunday Times children's books editor Nicolette Jones, who was chairing the panel.

She explained: "Some years ago I was chairing an event at the Oxford Literary Festival with both Michael and Frank on the platform, and Michael turned to Frank and said, 'Make a film of my Kensuke's Kingdom - go on, make a film of it.' And Frank looked as though he was too busy with something at the time - but I think that was the moment."