Carey Mulligan brings vividly to life a "loss of innocence" true story from pre "Swinging 60s" London.

Lone Scherfig's skilfully directed film of Lynn Barber's poignant memoir of growing up in England in the 1960s contains some outstanding performances in the main roles. In particular Carey Mulligan is utterly convincing as the sixteen-year-old Jenny despite the fact that the actress was herself 23 when the movie was made. For a mature young adult to play a girl in her mid teens takes a great deal more than just putting on a school uniform. Mulligan, with clever make-up (or lack of it) and thoughtful direction by Scherfig is every inch the clever, knowing but still innocent girl that Lynn Barber remembered. And her seduction by a man more than twice her age, David Goldman (Peter Sarsgaard), whilst perhaps morally repugnant is not something that Jenny fights at all against – as long as she can retain some control of events. It's her decision to lose her virginity on her seventeenth birthday and there is no coercion on Goldman's part - and it is her decision to chuck up the chance of going to Oxford University by leaving school early and becoming engaged to her lover.

Although Jenny is self-assured she is naïve not to realise that Goldman is a fraud. But she must at least have been reassured that her parents didn't ban her liaison with this much older man – indeed they are as much seduced by Goldman's charm as she is. This is the key plot element – the extraordinary fact that Lynn Barber's parents did not step in and warn her of the dangers of mixing with this credible but highly dysfunctional character. Not only is Goldman a liar and a cheat, although the full extent of this is not revealed until the end of the film, but he is also involved in borderline criminal activities in property. He was part of the shady world of the racketeer Peter Rachman a notorious exploiter of vulnerable tenants in London at that time. The vulgar high life of operators in this unpleasant world is well-illustrated in a series of scenes in which Jenny mixes with Goldman's business partner and friend Danny played by Dominic Cooper and his dumb blonde girlfriend Helen excellently portrayed by Rosamund Pike.

Nick Hornby's screenplay is tight and realistic and true to the period – as is Ben Smith's brilliant art direction. I was around in London at the time that the events take place and can testify to the extraordinary authenticity of everything visual in the film. It was a strange era for Britain was at the cusp of moving into the swinging sixties - as Philip Larkin wrote "Sexual intercourse began, in nineteen sixty-three…between the end of the "Chatterley" ban and the Beatles' first LP." For Lynn Barber/Jenny it began a tad earlier than that but the rite of passage that she went through was not unlike the experiences that many of her fellow baby-boomers will perhaps recall with the same mixed feelings. As it turned out because Lynn/Jenny eventually discovered Goldman's deceptions before it was too late she was able to escape his clutches, return to her studies and go to Oxford after all.

Peter Sarsgaard is very good as the rotten Goldman and you would not know that he is an American actor from Illinois – well done him, and well done his two voice coaches. There is also a fine cameo from Emma Thompson as Jenny's disbelieving and condemnatory headmistress. But the enduring memory for me will be of Carey Mulligan who gets so believably into the role of Jenny that it must be a candidate for an award when the Oscars role around again – she is that good.