JJ Connolly: Absolutely criminal

You might expect a London crime novelist to want to meet in an edgy Soho shebeen populated by colourful roués and off-duty coppers. JJ Connolly, the author of the cult novel Layer Cake, opts instead for the bar of the Sanderson Hotel, home to It Girls, lounge lizards and some of the West End's priciest cocktails. But he's happy. He's fed up with people wanting to take his picture against a brick wall covered in grafitti. Gatecrashing this type of gilded beau monde is far more what his book's about.

Layer Cake - now also the directorial debut of the Lock, Stock and Two Smoking Barrels producer Matthew Vaughn - reminds us that crime exists in every stratum of London society. Its anonymous narrator is a big-time cocaine dealer whose modus operandi is to keep a low profile, salt away his winnings, and go legit by the time he's 30. No flash motors and giving it large with shooters - he's a new, more refined breed of villain.

Although the book, and to some degree the film, are let down by a byzantine plot and sporadic lapses into cliché, it revivifies the tired and much-mocked London gangster genre. The action glides seamlessly from greasy spoons and crack dens to Palladian country clubs (a pivotal scene was filmed at Stoke Park). Reading it makes you feel as though crime - not love - is all around.

Connolly became a full-time writer five years ago. He was offered a book deal on his 40th birthday, and owes his current success to a remarkable sequence of events. Before the deal, he was working part-time on a flower stall in Angel, Islington, filling in time with painting and decorating jobs, writing whenever he could. Like many debut novelists today - former bus drivers, motorcycling vicars, and international con artists - his professional history is unusual, if not downright murky.

Connolly had limited formal education and left school at 16. Now 45, his CV is an A-Z of McJobs: market trader, trainee baker, shop assistant, street sweeper (the job of choice for punk rockers in 1976, apparently, as it was "practically impossible" to be sacked), plus the inevitable stints on the dole. He played guitar in a string of unsuccessful bands, and had a brief foray into acting in the 1980s - playing a speed-freak in the"clubbing" play, Zazou.

It was a spell in rehab 10 years ago that led to him getting the writing bug. "I was drinking too much, taking cocaine," he states matter-of-factly. "I was given the opportunity to go to a clinic in Wiltshire for six weeks, after which I spent a year in Brighton attending meetings. That was when I started writing. It's a very healing process. You get it all out and put it behind you. I've always had a mad imagination, so when I came out of rehab and got settled back in London I thought I'd give fiction a go and started writing a few short stories. I taught myself to type, and bought a computer out of a community shop window for a hundred quid - a big beast of a thing."

Connolly might have been just another wannabe with a manuscript in his top drawer, were it not for a fortuitous twist of fate. (If you're an aspiring novelist or scriptwriter desperate for your first break, look away now.) One lunchtime, he bumped into a woman he'd met a few weeks earlier at an art show. She asked him what he was up to. He told her he was going home to work on his book. "Really," she replied. "I'm a commissioning editor."

Less than a year later the book was in the shops, albeit with a tiny print run of 2,000. It soon became a cult hit, and a copy fell into the hands of the French Connection chairman Stephen Marks, executive producer of Lock, Stock and Snatch, who recommended the stylish thriller to Matthew Vaughn.

Vaughn made a mental note to read it, but put it on the back burner. Once again, Lady Luck stepped in. A friend offered Connolly a free ticket to see England play Germany in Brussels, and who should be in the same party on the Eurostar but Vaughn. They got chatting, and the wheels were set in motion. "A lot of people were offering to film Layer Cake at the time," Connolly recalls, "but I realised that in this country you can fit the people who can actually get a film made into one room - and Matthew's one of them. So I hitched my wagon to his."

Impressed by Connolly's punchy use of underworld argot, Vaughn asked him to write some dialogue for Ska Films' subsequent release, Mean Machine (which starred Vinnie Jones). He even got a cameo in the film, playing Barry the bookie. After various legal wrangles, Vaughn finally bought the rights to Layer Cake in October 2002, and Connolly was signed up to adapt his book into a screenplay. By June 2003 they were shooting. In the film world, this is about as precipitous as it gets.

Layer Cake the movie is an assured and refreshingly banter-free take on London lags up to no good. In yet another stroke of good fortune, the cast includes Sienna Miller - an unknown newcomer at time of casting, now Jude Law's girlfriend. Daniel Craig, now stepping out with Kate Moss, shines in the lead role of the anonymous narrator. And with Vaughn's direction showing impressive visual verve, the signs are encouraging.

Connolly is delighted with the film and believes that when the inevitable comparisons between Vaughn and Lock, Stock's director Guy Ritchie start to happen, Vaughn could well come out on top. He also approves of Daniel Craig's casting. "I like the fact that he's classless," he says. "If people go and see a crime movie and the voiceover starts in a Cockney accent like mine, they're going to go: 'Awww, here we go...' The whole point of Layer Cake is that it's about infiltration. The narrator's the kind of bloke who could go to a caff in the morning and Gordon Ramsay's in the evening and not feel out of place."

The fluidity of class is one of Connolly's obsessions. He grew up on the Red Lion Estate in East Finchley - dubbed "Hungry Hill" by locals - the son of Irish immigrants. His father was a gambler and alcoholic who abandoned his mother to look after John and his brother Mick. The pressure of bringing up two boys in what remained a strange and daunting city hit their mother hard. She succumbed to bouts of mental illness, whereupon the boys would be packed off to Catholic foster homes. Although he was a tearaway and shoplifter, JJ insists he was a poor thief with a knack for getting caught. His criminal days ended in his teens when - after being nicked for stealing a case of Scotch from a local football club - he was told by a policeman (or "cozzer", as one of his characters would put it): "You're not very good at this thieving lark, are you?"

The years passed, and so did practically every type of job imaginable. With one exception. Connolly is adamant that he has never been a cocaine dealer. "Don't worry," he says. "You won't get anyone jumping out of the woodwork saying, 'Oh yeah, I know JJ Connolly - he used to sell drugs.' I'd be a very bad drug dealer. If you're a drug dealer, you've got to scare people. I'm the least threatening person I can think of. Anyone who thinks I'm a gangster has obviously never met a real one."

YetLayer Cake is a novel that oozes authenticity. The passages describing the nuts and bolts of Class-A distribution, for example, have a worrying authority. Connolly insists this is simply because people tell him things. "Rehab isn't fun," he says. "You turn yourself inside out. But you meet people who have really lived. There aren't many shallow people in rehab. Everyone's got stories to tell." Certain Layer Cake "consultants" will have to remain nameless, however. Connolly may not be a criminal himself, but he will admit to knowing people who have "ducked and dived a bit, been up to all sorts". They helped out with the finer details.

Even though people assume he spends his days now hanging out with Madonna and Claudia Schiffer (Matthew Vaughn's wife), Connolly insists his close friends are the same gang he's hung around with for years. One is a shirt-maker, another works in PR, there's a portrait painter, a florist... in short, not exactly London's criminal underbelly. He lives in King's Cross with his commercial-producer girlfriend of three years, Rebecca, and is busy with his next book.

"It's a sort of Lord of the Rings of the criminal underground," he says. "A quest." He treats writing like a job, setting himself a target of 1,000 words a day. And he's bought himself a laptop.

The new edition of 'Layer Cake' (Duckworth, £7.99) is published on 9 September. The film is released on 1 October