It's the greatest story ever told. I'm not referring to George Stevens' 1965 biblical epic chronicling the life of Jesus Christ, but the tale of how four gobby scousers changed the world. This week, as part of its Fatherhood season, BBC Four screened Lennon Naked, a TV film looking at John's troubled relationship with his father and starring Christopher Ecclestone as the late Beatle.

The Beeb have been trailing the drama since the start of the year and its title was filled with promise. OK, stop giggling in the cheap seats; anyone who wants to see John wearing little more than a pair of NHS specs - and to confirm if he really was bigger than Jesus - only has to check out the sleeve of his and Yoko Ono's Two Virgins album. No, the title Lennon Naked suggested an unplugged study of John's late 60s/early 70s life, in much the same way that 2003's Let It Be... Naked stripped away producer Phil Spector's Wall Of Sound orchestras and choirs to reveal the band's orginal vision of a back-to-basics album. It promised to do for this period of John's life what 1991's excellent The Hours And Times did for the early days of Beatlemania, exploring the man instead of the myth.

Unfortunately, writer Robert Jones and director Edmund Coulthard have referenced so many aspects of John's life that Lennon Naked more closely resembles a sensation-overload Sgt Pepper's. Indeed, now we know how many semi-realised themes and plotlines it takes to fill the Albert Hall. The relationship between John and his father Freddie is buried beneath did-they-didn't-they? scenes with Lennon and Beatles manager Brian Epstein, the breakdown of John's marriage to his first wife Cynthia, internecine band squabbles, messianic delusions, worshipping false prophets, Apple Corps failing to make a profit and, of course, the ballad of John and Yoko.

A Fab Four psychologist would probably argue, possibly correctly, that all these strands of Lennon's life are intrinsically linked to his early traumatic rejection by his father and his mother Julia. But shoehorning them into a 90-minute drama can only result in a hazy kaleidoscopic impression of events, rather than a keenly focused drama. After all, it took the Beatles themselves more than 11 hours to tell their story in the Anthology TV series and even then they barely scratched the surface of their Satyricon-like 60s existence.

On the plus side, the performances in Lennon Naked are very good. Eccleston sounds more like Ringo than John and he's about 20 years too old for the part, but otherwise he manages to nail the complexities of the man (in interviews, he's described Lennon as 'kind, brutal, funny, arrogant, insecure, passionate and brilliant. In short, human'). Naoki Mori does her best with an underwritten Yoko, while Adrian Bower provides an everyman moral centre as John's lifelong friend Pete Shotton. Christopher Fairbank gives a marvellously ambivalent performance as Freddie, blurring the margins of the errant old seadog's motivations as the viewer also sees him through John's uncertain eyes.

Nevertheless, for a film that's designed to be about paternal relations there are too many omissions. For example, John repeating the sins of the father with his own son Julian is highlighted, but there's no reference to Feddie's own difficult childhood in an orphanage. Lennon Naked is a chaotic Revolution 9, when it could have been a beautifully crafted Strawberry Fields Forever.

Colin Houlson