I type this review through a cloud of desire – not my usual low-level lust, but passionate, Beatlesmania-style yearning for Aaron Johnson. It is as if he was cast not for his resemblance to Lennon, but rather his ability to induce the kind of giggling swoon that Elvis could in the fifties. We see John Junior realising the possibilities of being The Guy in the Band in an early scene in a cinema full of screaming teenage Liverpudlians, watching black and white footage of a thrusting Presley. However, Johnson is a fully realised rock and roll star merely by virtue of his cheekbones, rather than a drop-out kid with glasses who has yet to pick up a guitar.

The film follows the teenage Lennon seeking out his estranged Mother, who for various reasons gave him up when he was four, leaving him to live with his loving but puritanical Aunt Mimi. When he does find her, Julia almost too conveniently represents the lure of rock and roll, clicking on a jukebox and twirling John round to hits like ‘Shake, Rattle and Roll’. Reviewers have already commented on the Freudian relationship between John and Julia – at times she treats him more like a toyboy than a son, kissing him effusively and taking him out dancing. Indeed Julia is depicted as John’s first love – he flirts arrogantly and artfully with girls his age, but the only ‘romantic’ scenes are with Julia, when she tells him to ‘Kiss Me Quick’ as they run down a Blackpool pier, or they lie on a sofa together listening to Screamin’ Jay Hawkins’ ‘I Put A Spell On You.’

Adoration aside, Johnson puts in an excellent turn as Lennon, capturing his wit, his repertoire of impressions, as well as his ability for cutting cruelty. The film is prettily shot, especially the Julia scenes, which are sped up into dizzying fast-motion or slowed down, reflecting their transient, dreamlike quality. I have an enduring love for Kristin Scott-Thomas, so even if playing the self-contained, crisp-voweled Aunt Mimi isn’t much of a stretch for the queen of cut-glass repression, her performance is nonetheless excellent, and her solo scenes nervously waiting at home for an absent John are brutally affecting. Thomas Sangster (scrawny lovelorn Liam Neeson-spawn in Love Actually), puts in an incredibly weak and irritating performance as Paul McCartney. In scenes of high emotion, Sangster cannot begin to match Johnson’s acting abilities. Apart from minor criticisms, this more than competent film examines an interesting, generally unexplored period in Lennon’s life, and treats its subject with just enough irreverence that we see him as a human rather than an icon.