The comparison isn't exact, but it's close enough. Just as, in the 1970s and 80s Bronx shyster Stanley Kubrick happily filled the 'magus' hole required by American directors and critics, so Mike Leigh and Ken Loach occupy the 'genius leftist auteur' hole required by British cinema in the 90s and 00s. Despite the widely acknowledged differences in their approach and films, the two are often handily bracketed together – there's a 'safety in numbers' aspect to their continuing, unjustified lofty status.

Both are competent directors capable of eliciting strong performances from their actors – and both have distinctly above-average films in their back-catalogue (the beloved Kes still holds up; Topsy-Turvy, which has seemingly become an annual BBC TV fixture, repays repeated small-screen viewing) though nothing outstanding from a global-cinema perspective. Both are articulate, 'committed,' and visibly – perhaps even ostentatiously – serious individuals.

With Leigh, a special mystique attaches itself to his well known but nevertheless always slightly mysterious script-writing process, which relies on (ostentatiously) exhaustive research, and improvisation via extended rehearsal. In theory, this means that Leigh has a particular respect for and bond with his actors – but if that's the case, what are we to make of the reports, apparently accurate, that Leigh with-held the subject matter of his latest movie Vera Drake – abortion – from all cast-members apart from his star, Imedla Staunton?

This was supposedly intended to ensure a vivid reaction when the characters playing Vera's close family (Phil Davis as husband Stan, Daniel Mays as son Sid, Alex Kelly as daughter Ethel, Eddie Marsan as Ethel's fiance Reg) discovered her secret. But isn't this what actors do? Didn't Leigh trust the likes of Davis to be able to act surprised? It's the same cheap trick Ridley Scott pulled when the Alien burst out of John Hurt's chest, showering his Nostromo colleagues with Kensington Gore – and sending Veronica Cartwright into an all-too-genuine screaming fit.

And elsewhere in the film all of these actors show themselves emphatically capable of convincing work: Marsan is remarkable as the hapless Reg, unrecognisable from Benicio Del Toro's religious pal in 21 Grams. And while Kelly sails perilously close to patronising caricature as the painfully timid Ethel, the character does function in terms of the overall Drake family dynamic: growing up in the shadow of a mother as down-to-earth saintly as Staunton's Vera has clearly not been an entirely pleasant experience for her introverted daughter.

Calling her 'Ethel' was risky, however – the character is already slightly too reminiscent of the timid daughter Eth from 1940s/50s radio sitcom The Glums (a title which applies to the Drakes with increasing aptness as events unfold and the previous, welcome glints of humour rapidly evaporate). Eth's boyfriend was Ron, Ethel's is Reg – some kind of submerged Kray-twins/Glums in-joke from Leigh? On a similar level, couldn't Leigh and company have come up with a different name than Vera Drake? It's hard to think, given the context, of a more unfortunate set of initials.

Then again, this would actually be a much better film if the title was Lily Clarke. Lily – a supporting role socked over in searing style by Leigh regular Ruth Sheen (she provided several highlights in All or Nothing) – is Vera's lifelong friend, and the woman who puts her in contact with the girls and women she 'helps out'. While Vera takes no payment, Lily always levies a charge – she also makes a tidy living selling sugar and similar kitchen supplies. Though entertaining in her gimlet-eyed harshness, capitalistic Lily is not a sympathetic character – just in case we miss the point, Leigh has her make disparaging remarks about immigrants, with which Vera immediately disagrees.

Making a woman as amoral, devious and unpleasant as Lily the abortionist central character would have added welcome complexity to a film which, for all its achievements, admirable sentiment and laudable aims, is ultimately let down by a script which is often unforgivably sloppy and crude. What Leigh presents is the ordeal of Vera Drake – a wonderful wife, mother, daughter, neighbour. A model citizen in every way, apart from the fact that by carrying out abortions she is breaking the law.

But this law was scrapped in the late 1960s, and we (in Britain) now see that "backstreet" abortionists were a necessary evil, fulfilling a social need caused by archaic legislation (though of course in many countries abortion is still outlawed – and if the religious right in the US has their way, Roe v Wade may soon be overturned). So even though she's a criminal, Vera is a noble one – at the end, Leigh briefly introduces two other illegal abortionists, whose methods are much more drastic than Vera's, just to cast her in an even more positive light. We also see how this is very much a class issue – a posh girl for whose family Vera cleans is raped, and because of her money and connections a legal abortion is discreetly arranged (this subplot, frustratingly, is a dead-end which never reconnects with the main narrative).

We get Leigh's point: but the trouble is, we aren't given enough evidence to decide whether Vera's techniques are dangerous or not: we see several 'clients' of hers but, like Vera herself, we don't see the aftermath of her interventions, apart from in one case. This is the incident which causes Vera – after "about 20 years" of "helping girls out" – to come to the attention of the authorities. Things go wrong, leading to the 'patient' becoming gravely ill: and because the girl's mother used to work with Vera before the war, she's able to identify her to the police. This would appear to be a remarkable coincidence – and thus a very shaky foundation on which to pivot the whole film. And any viewer who recalls that a similarly unfortunate coincidence set up the turning-point in All or Nothing is unlikely to give Leigh the benefit of the doubt on the issue.

What follows is the harrowing arrest, detention and trial of Vera Drake – whose painful inarticulacy results in several protracted scenes in which the police attempt to elicit statements. Staunton's performance here (as throughout the picture) is powerful and impressive – but there's something slightly exploitative about the way Leigh lingers on Vera's emotional duress. This cheery, benevolent woman is put through the impersonal police wringer before our eyes, and such is the verisimilitude of Staunton's performance – in a film whose evocation of post-war detail is consistently excellent – we feel that we, too, are going through every ounce of the agony (credit to production designer Eve Stewart and cinematographer Dick Pope).

The film becomes, in effect, The Passion of Vera Drake, joining a cinematic lineage which encompasses most recently Mel Gibson's The Passion of the Christ and stretches back to Carl Theodor Dreyer's The Passion of Joan of Arc. Dreyer's disciple Lars Von Trier now specialises in ordeal-of-the-female-innocent exercises: Nicole Kidman in Dogville, Bjork in Dancer in the Dark, Emily Watson in Breaking the Waves. Can it be a coincidence that Leigh has cast Sandra Voe – who Bess's mother in Breaking the Waves – as Vera's own ancient, bedridden mother here? (She's remarkable in her handful of brief appearances, by the way.)

With Von Trier, there's always the sense that his films – though dealing with ostensibly serious issues – aren't to be taken seriously. But Leigh's engaged, sagacious, contemplative image is a world away from that of Copenhagen's puckish Copenhagen uber-prankster – a shame, then, that a picture like Vera Drake fails to address such a grave (and, sadly, still topical) subject with the complexity and intelligence it deserves. We're thankfully still a very long way from the likes Lilja 4-Ever or Take My Eyes, with their thuddingly clunky "treatment" of pressing issues: Vera Drake is skilfully made in nearly every degree. But as the proverbial 'nearly' pregnant woman would attest, 'nearly' can be a very big word indeed.

Neil Young

11th January, 2005

VERA DRAKE : [6/10] : UK (UK-Fr) 2004 : Mike LEIGH : 122 mins approx