Gleefully scaling the fourth wall (the invisible divide that suspends our logical disbelief at cinematic storytelling), the three principal members of the radio and TV comedy team, the League of Gentlemen, land fleet-footed on the other side. They find they are certainly not in Royston Vasey anymore. They're not even in Spent, the name of the village in their radio days. The conceit that characters enter into the 'real world' in order to prolong their existence is not a new one (but then neither is 'boy meets girl' and Richard Curtis is, Hugh Granted, quite rich, thank you). The interest and excitement is not from the genre itself, it's the way it's abused. And the League thrives on abuse, self or otherwise.

In attempting to divest itself of its most famous creations, the League has bent things out of shape to fit the big screen and as with all TV to movie adaptations (which the movie acknowledges with more than a wink), the result is never wholly a movie and obviously neither is it a TV show. It's a mutant hybrid, like the creature created from spare parts of zoo animals in their 1st series. That said, if you're a fan, you'll love what they've done with familiar Vasey residents and if you're introduced to the League via Apocalypse, then it depends if you enjoy watching voluminous gallons of giraffe 'issue' being ejaculated onto 'a load of old biddies'. The simple expectation of what can happen when you let Mark Gatiss' inept vet Dr. Chinnery anywhere near organic life is usually enough for me. What he did to that tortoise in the TV series still makes me smile in a way my loved ones would not appreciate.

I wonder if I'm alone in thinking (and therefore unfashionable, heaven forbid but then I can't 'text' without spelling and punctuating every word correctly) that Little Britain is Les Dawsonesque but regarded widely as being ironic (so that's OK, overload them with awards). A significant percentage of its impact, for me, is in the writing and performance of the voiceovers. Tom Baker was born to narrate Little Britain. Yes, Walliams and Lucas are very talented performers but the gags tend to be rooted in the usual stuff we sometimes blithely condemn for its non-PC-ness. It's Ben Elton doing his 'tits' sketch condemning the laughs while he still gets the laughs from the same material but he fiercely pretends to stand at a 'right on' tangential angle to it. As Elton is now aligned with Andrew Lloyd Weber, we have to accept that the world has moved on. Humour is not as easily pigeonholed. Where Little Britain really scores are the sketches that cannot possibly be thought of 'funny' in advance. Written down, the words must stare at the performers daring them to invest some comic invention into them. Yesssss.

The classic example from times past is the stand out surrealist moment from Monty Python. Michael Palin has said that he can judge whether his humour will be compatible with another's by gauging their reaction to one of Palin's (and Cleese's) finest moments - the Fish Slapping Dance. The fact that Cleese almost loses it makes it even funnier. If you're not familiar with it, be so quickly. Even the music is surreal. The fact I shared a flat with the person who was the Fish Slapping Dance's film editor's assistant still makes me glow with pride. Anna Gregory, take a bow.

I got into the League's TV series slowly. At first, I could appreciate the talent on display (it felt like The Comic Strip Presents with added morbidity) but it was far more dark than humourous (belly laughs were not encouraged by this talented foursome (the performing threesome and the unseen Jeremy Dyson, co-writer) and until the one defining moment in the second series, I was vaguely but hypnotically attracted to it. It had an unhealthy grip, no question, and the third series really did attempt a different form, one that was successful in my evaluation. But I still preferred my comedy laugh-out-loud. I watched, I appreciated and groaned with pleasure every time Tubbs and Edward burned up the airwaves. But it was still flying low, under my Black Books/Father Ted radar.

This all changed with the arrival of Papa Lazarous.

Now I cannot be alone in being deeply affected by this bizarre creation. How else could you explain that a one note gypsy, blacked up like a minstrel, with a voice like a drain Domestos fled in terror from, is so wonderfully disturbing? Reece Sheersmith's creation (always looking for 'Dave' and preying on old women) is an alarming reminder that some prejudices or assumptions of behaviour still can be perverted with a great jolting shock. Papa Lazarous is a psychotic Krusty the Klown, a deranged figure who holds a fascination to those who have felt his power like no other TV character. He has turned up live in Drury Lane to tumultuous applause and just had to be in the movie but wisely (because like the best and most lethal poisons) the League instinctively knew that he is more effective in small doses. For some reason his catchphrase "You're my wife now…" is utterly chilling.

Finding a portal to the 'real world' while their own seems to be literally going to hell, three of Royston Vasey's more 'B-type' characters slip into the London of today and try to meet their makers. The one joke but double entendre'd Herr Lipp is joined by Hilary Briss, the butcher with the heart of a young boy (at £4.50 a pound, £4.99 if you consume it on the premises) and that gag's not the League's but neither is it mine. It all started with novelist Richard Matheson. It was said of him that he had the heart of a ten year old and he kept it in a jar on his desk. Joining the paedophile and cannibal is the ordinary guy (but hugely Northern in a way that Christopher Eccleston is not), Geoff. It's a good cross section of known characters and the movie is never less than entertaining for their specific inclusion.

They reach the Smoke and descending on Soho Square, they find their real life counterparts. It's a credit to the performances to note that when Sheersmith is playing the 'real' Sheersmith, he's an egomaniacal, media bastard who whines at not being paid for a charity gig. The presumably self effacing Mark Gatiss, (whose career high was defending how scary his Dr. Who episode was on Radio Four) plays self-effacing to a 'T' while the stout Steve Pemberton (the only Leaguer with a 'normal' family on screen) is the terrified but bemused hostage the Vasey threesome kidnap having his severely altered ego take his place. One of the darker aspects of the movie is having Herr Lipp becomes a surrogate father. What games does he play with his 'kids' while his 'wife' is away?

To exorcise Royston Vasey, the League is writing a new world, a middle ages full of devil worshipping fops and dark magics. As that reality shift is played out, Geoff inserts himself into the screenplay and becomes a hero with no more expectation in that life than being known for having a big dick. Royston Vasey's inhabitants have ambitions very much below their stations and waistlines. David Warner has great fun as the Darth Vader of the League's third world (he conjures up demons as effortlessly as he once killed off minions as Supreme Evil in Gilliam's superior romp, Time Bandits).

What comes across as surprising is the fact that you come to actually care that Royston Vasey is dying and you are urging on its fictional inhabitants to find some sort of life beyond the fickle League's whims and creative aspirations. The climax - at a church so Sheersmith's egregious female clergy woman can enter the fray - is as off the wall as you'd expect. And there is a moment of exquisite shock in the graveyard as the 'real' League realise that Royston Vasey's predicament is for real. Let's just say that this is the League's take on laughing one's head off and it comes as a genuine shock.

So after all this meticulous interweaving, Dennis Potter-like, of worlds, times and fictions, how come the very best comedic moment belongs to a middle aged woman (Pemberton's terrifying Tubbs) sitting on a toilet in the first five minutes? It's a credit to the writing that I still smile at 'her' utter surprise at what most of us take for normal bodily functions.

I don't think I can look at fish in the same light ever again...