The film is based on a genuine 1950s novel.
Journalist Colin McInnes wrote a set of three "London novels": "Absolute Beginners", "City of Spades" and "Mr Love and Justice". I have read all three. The first two are excellent. The last, perhaps an experiment that did not come off. But McInnes's work is highly acclaimed; and rightly so. This musical is the novelist's ultimate nightmare - to see the fruits of one's mind being turned into a glitzy, badly-acted, soporific one-dimensional apology of a film that says it captures the spirit of 1950s London, and does nothing of the sort.
Thank goodness Colin McInnes wasn't alive to witness it.