The Mother (2003), directed by Roger Michell. English. 111 minutes. Tuesday (12/10), 21:00, BBC4. Not available elsewhere.

It’s a pleasure to be able to recommend a film that you won’t be able to stream or download. I was able to track it down eventually, on a Russian pirate site, but I wouldn’t particularly encourage anyone else to follow suit. An accelerating sequence of pop-ups tries to batter you into handing over your credit-card details. Such is the modern internet.

The Mother is a small film, in the sense that it only has seven characters and a plot you could jot down on the back of a Baroness’s business card: widow sleeps with daughter’s boyfriend. If we have learnt anything from quantum physics, however, it is that the most powerful things often come in small packages, and this British film, written by Hanif Kureishi, once the bad boy of Bromley and Wardour Street, is no exception.

Anne Reid, a hard-working character actress once tabloid famous as the tragic wife of Ken Barlow in Coronation Street, plays May, a traditional Northern wife and mum. She comes to London with her fading husband, Toots (brilliant Peter Vaughan), to stay with her indifferent, wealthy son Bobby and his brittle wife Helen. Toots dies a heartbreaking natural death, after declaring his love and pride in his horrible family. Unable to face going home, May moves in with her daughter Paula, a schoolteacher and would-be writer who is conducting an affair with her brother’s friend and handyman, Darren (Daniel Craig).

Toots’s death, and May’s experience of the selfishness and unkindness of her family, propel her into recklessness. Drawn to Darren, who is one of those posh university dropout handymen who like poetry and art, she first forms a friendship with him and then rapidly embarks on a full-on sexual affair. Reid was, by my reckoning, 68 at the time: Craig was 35, and playing younger. Her transformation from dowdy, downtrodden spouse (‘Some men like their wives depressed,’ remarks Darren) to beautiful, passionate woman, through the power of eros, is astonishing to behold. However, sexual liberation does not come without consequences in a world of obligation, jealousy and self-interest. May’s newfound capacity for sexual love conflicts horribly with her role as mother to the venal Bobby and desperate, over-therapied Paula. (A wonderful performance from Cathryn Bradshaw, then known for a supporting role in the BBC’s Oranges Are Not The Only Fruit. She has no recent credits.)

Kureishi’s vision of London in the Cool Britannia era is brilliantly and unflashily realised by Michell, who died a couple of weeks ago: he understands that camera movement, the rhythm of shots, slo-mo, transitions, etc, are not stylistic gestures to be ticked off by critics and film lecturers but tools for invoking emotion.

May and Toots, who come from an earlier era of economic constraint, modesty and respectablity, are suddenly plunged into an era of capitalist excess. Greed is good (as it had been ten years earlier). Property speculation and trading are seen as an escalator to wealth. Rich men, permanently glued to their mobiles, supply their neglected wives with hopeless loss-making ‘businesses’: Helen, for instance, has a shop selling only cashmere clothing. Children are left with nannies and electronic child-minding devices. Art, poetry and education have become lifestyle accessories, badges of tribal allegiance, rather than fuel for the soul. Everyone is unhappy.

What we are experiencing in Britain is a kind of horror-comic reboot of the early 2000s. The only difference I can see between Kureishi’s London and our beloved Cotswolds is the drug culture. SSRI anti-depressants had not yet arrived, but recreational psychotropics were common. Even so, it takes a good hour before we see Craig applying his elegantly quivering nostrils to what we used to call the Colombian Marching Powder and promptly losing his humanity. In a realistic film about modern moneyed Gloucestershire, that would have to happen during the opening credits.

The Mother is an excellent, cathartic film that reminds us of what British-based actors, writers and filmmakers could do when they were not in bondage to the Philistines from across the water.