Bruce Robinson at work on Withnail and I [Murray Close]

I DON’T know about you but I went right off François Truffaut when he said that British cinema was a “contradiction in terms”.

I’d like to think our plucky little island often punches above its weight when it comes to films. I mean, what other country could have given the world The Third Man, Great Expectations, Local Hero, 2001: A Space Odyssey, Kes, Trainspotting, Holiday on the Buses? Well, you can’t get a coconut every time.

For obvious reasons we’re particularly adept at producing low-budget movies stuffed to the gunnels with eccentrics. A prime example of this is Bruce Robinson’s tragi-comedy, Withnail and I, the subject of an affectionate appreciation by Toby Benjamin entitled Withnail and I: From Cult to Classic.

For those unfamiliar with the – for the want of a better word – plot, Withnail is the tale of two impecunious unemployed actors living out the fag end of the 60s in a squalid Camden Town flat. Bored and frightened, they pile into a clapped-out, one-eyed Jag to sponge off Withnail’s predatory uncle in Cumbria for a while. They return to learn that one of them is about to be plucked from obscurity and poverty, leaving the other behind. And that’s it.

What makes the film so memorable is not what happens but how it happens. A paean to excess – particularly alcohol – it’s quite rightly been described as akin to a hangover.

It does, however, contain possibly more quotable lines than any other film. Few fans can enter a tearoom without at least thinking of ordering “the finest wines available to humanity” or lamenting they’ve “gone on holiday by mistake” or fingered “a firm young carrot” in Morrisons. Mind you, in these enlightened times it may not be a good idea to flip down your shades and shriek “Scrubbers!” at a posse of passing schoolgirls.

I’m afraid if you don’t know – and love – the film, this will all seem a total mystery to you. I’m tempted to say that if you do not know it you may as well go and watch Homes Under the Hammer but I’m hoping a few Withnail virgins will be intrigued enough to seek it out.

You see, Withnail is that most English of English films. It’s essentially the kind of film Ealing Studios would have made had Micheal Balcon not been such a prude… and 30 years later.

The film made a star of Swazi-born tee-totaller Richard E Grant. Walking the tightrope between comedy and tragedy, he pulls off the not inconsiderable feat of making Withnail likeable. Top-billed Paul McGann was Marwood, the “I” of the title. A less showy role, he’s basically Robinson himself.

The film’s – entirely male – supporting players are no less effective. Ralph Brown is inspired casting as the hair-obsessed dope-head Danny, creator of the “Camberwell carrot.”

And the wondrous Richard Griffiths is perfection as Withnail’s lecherous but loaded Uncle Monty, given to spouting quasi-profound drivel dripping in innuendo. “I think the carrot infinitely more fascinating than the geranium,” he says at one point.

“The carrot has mystery. Flowers are essentially tarts. Prostitutes for the bees. There is, you’ll agree, a certain ‘je ne sais quoi’ oh so very special about a firm, young carrot.”

The reason the film is so quotable is due to its starting life as a novel and its gestation period being so long. Writer/director Robinson started writing it in the 60s; it was released in 1987. But then, as fan boy Charlie Higson reminds us, unusually, the script reads funny.

Robinson based the film on his time living in a real-life squalid flat in Camden Town with his friend Viv MacKerrell, the inspiration for Withnail.

“That Camden Town period of my life was all about cheap red and getting smashed on ‘pot’ as it was then known,” says Robinson. “Perhaps one of the reasons the film survives is that nothing changes – people are still doing that, although no longer in Camden Town – all the wankers’ caffs have acquired an ‘e’ at the end.”

Ironically, for a film with Camden Town at its very heart, much of the movie was shot elsewhere. For example, The “Mother Black Cap” pub – obviously inspired by The Mother Red Cap – was in Westbourne Park. You can clearly see Erno Goldfinger’s Trellick Tower – a building Robinson loathed – in the background. The pub was, of course, demolished in 2010 and is now – surprisingly – a block of flats. Similarly, the fetid Camden Town flat, home to that terrifying sink, was in Bayswater and the caff, with that drippy egg sandwich, was in Ladbroke Grove. At least that’s Regent’s Park in Withnail’s melancholy Hamlet-spewing final scene.

Toby Benjamin’s handsome book is clearly a love letter to the film, bulging with great photos, snippets of behind-the-scenes gossip, interviews with what the remains of the cast and crew and fans’ observations. The publishers have done him proud.

I have a Withnail-obsessed friend given to endlessly spouting quotes from the film – mainly “I demand to have some booze!” This year’s Christmas present won’t be a problem.

• Withnail and I: From Cult to Classic. By Toby Benjamin, Titan, £39.99