Lennon Naked, BBC Four

Films about rock stars usually fail, because it's impossible to recreate whatever larger-than-life qualities made them unique and famous in the first place. You frequently end up with a slightly embarrassing party-piece impersonation that captures some of the mannerisms but misses the essence of the character.

John Lennon continues to exert a strange fascination for film-makers, doubtless because he's the Martyred Beatle, but previous biopics have shrewdly homed in on lesser-known aspects of his life, so you weren't constantly comparing the celluloid version with what you knew of the real person. Sam Taylor-Wood's excellent Nowhere Boy dissected the pre-Beatles Lennon, while I'd wager that nobody will surpass Ian Hart's uncanny performance in the Hamburg-era flick, Backbeat.

There was hardly any sense of the Lennon in the film being involved in music at all

But Lennon Naked took the plunge into full-force Beatledom, dropping in on strategic moments of the Moptop saga between 1964 and 1971. Christopher Eccleston certainly looked like his subject - except for the unavoidable fact that Eccleston, at 46, is too old to play Lennon in his twenties - and he'd obviously been poring over his copy of Speak Better Scouse until the pips squeaked. When his long-lost and woefully wayward dad Freddie (Christopher Fairbank) reappeared after a 17-year absence, unleashing John's black torrent of primal pain and emotional angst that were the film's theoretical subject, it threatened to go all Harry Enfield ("are youse sayin' our mam's better'n'our nan? Ay? Ay? Ay?" etc). Only the orange Afros were missing.

Actually a bit of frivolity might have worked wonders, because over its 90-minute span Lennon Naked progressively suffocated in its own earnestness. We know Lennon could be vicious and acerbic, but he also wielded a savage wit which wasn't captured here. In scenes which laboriously sought to reconstruct Beatle press conferences, Lennon was seen hectoring the press like some drab cultural commissar, when his real-life performances were gleefully skittish and surreal. This Lennon was so bitter, angry and dessicated that he seemed like a lonely failure approaching the end of his life, rather than one of the planet's most celebrated artists going through a patch of professional and emotional turmoil.

Use of newsreel footage to anchor the timeline became more damaging than helpful, because it kept offering little flashes of the charismatic aura that surrounded the slightest manifestation of Beatledom, which promptly vanished again when we returned to the fictional action. Though Beatle and Lennon music featured on the soundtrack, there was hardly any sense of the Lennon in the film being involved in music at all, other than a scene where he improvised some peculiar noises with Yoko Ono. And on the topic of bad impersonations, whoever cast the other three Beatles deserves either the sack or at the very least a new pair of specs. Homer Simpson would hardly have looked less like Ringo and George Harrison than the actors who'd been cast, while the one I'm pretty sure was McCartney did a kind of arch, plummy-voiced turn that recalled Neil Tennant of the Pet Shop Boys at his most pontifical.

Above all, there was a deathly emptiness at the heart of Lennon Naked which made it a real struggle to sit through it to the end. It was as if Lennon existed in a personal vacuum punctured only by occasional appearances by his despised first wife Cynthia (Claudie Blakley), his thuggish driver who looked like Vinnie Jones, and a mate called Pete. Then he met Yoko, and there was only John and Yoko. Lennon's climactic confrontation with an understandably uncomprehending Cynthia had him speaking the kind of lines you might think of a couple of days after you've had an argument with someone, and wish you'd actually said at the time - "I must have loved you once but I don't any more," or "You or her? Then it's her. Have it all. You won the pools."

Perhaps the problem with Robert Jones's screenplay was that it tried to reconstruct Lennon from the outside, using sources like Jann Wenner's Lennon Remembers interviews, rather than taking greater licence to find a more poetic kind of truth. Whatever the reasons, I couldn't believe in this self-obsessed, primal screaming John Lennon as pop star, counter-culture icon, FBI surveillance target and all-round upsetter of applecarts. I'm off to read Ian MacDonald's Revolution in the Head again to make me feel better.

Watch a clip from Lennon Naked