'Royle' pair reuniting for comedy film
The Fattest Man is expected to be released in cinemas then broadcast on terrestrial television.
Harries said: "It's early days. It is about the UK's fattest man – he's trying to work out if the kudos of having that title is worth sacrificing his life for. It will definitely have a splash of The Royle Family in it."
The film is being developed by Harries' Left Bank Pictures with ITV Productions, which made Royle, but has not yet been cast.