By Caroline Briggs
BBC News entertainment reporter in Cannes
Monty Python star John Cleese is writing the next feature film for Aardman Animations, the makers of Wallace and Gromit have announced.
John Cleese is famed for his comedy skills
Aardman co-founder Peter Lord said the Fawlty Towers actor was currently writing the "pre-historic comedy".
It will be their fourth feature-length film in a deal with US film studio Dreamworks.
Their previous box-office hit was Chicken Run, with production still under way on Flushed Away.
Lord made the announcement at the Cannes Film Festival on Thursday.
An inflatable Gromit greeted Cannes festival-goers and tourists
He said the new film was still in the early stages and would follow after Flushed Away, which is due to be released in 2006.
"It will be great comedy adventure about a pre-historic culture clash between two tribes, one comparatively evolved tribe, and one un-evolved tribe," he said.
"Some might consider one tribe might be the English, and some might consider that the other to be the French, the Gauls.
"Let's just say it's the start of the Entente Cordial and it explains why the English Channel is there."
Lord was also joined at the festival by the Oscar-winning Nick Park to reveal a sneak preview of The Curse Of The Were-Rabbit, which is also in production and due to be released in the autumn.
Wallace and Gromit's next film is The Curse of the Were-Rabbit
It is the latest Wallace and Gromit adventure to follow-up the TV successes of A Grand Day Out, The Wrong Trousers and A Close Shave.
The film features the voices of Helena Bonham Carter, Ralph Fiennes and comedian Peter Kay.
It follows Wallace (Peter Sallis) and his dog Gromit as they hunt for a mysterious beast which is destroying the entries in the town's Giant Vegetable Competition.
Park, the winner of three Oscars, said filming of the final action scenes were still under way and described the film a "close encounter of the 'furred' kind" with lots of horror film references and characters.
Earlier in the day, a 30ft-high inflatable Gromit was unveiled on the Croisette to publicise the film.