The end of Ali G - for real

Dan Mazer is holding court, intermittent chuckles lighting up his face, as he lifts the lid on how two struggling comedians from north London conquered the world with outrageous cunning. Mazer himself is pretty obscure - it is his writing partner Sacha Baron Cohen and their creation, Ali G, that you really know. "I tend to pick the targets," he explains.

"For the new show, Ali G in da USAiii, Sacha said things like, 'I want to get George Bush or Bill Clinton', and I had to explain to him that it's not very realistic that Dubya would break off from a press conference on Iraq for an interview with Ali G. But it doesn't matter if the targets are old or young, Right-wing or Left, it's all about puncturing pomposity."

It is about making money too - the Ali G phenomenon has become a franchise worth £30 million and with a film, several TV series and books too, it has brought Baron Cohen the sort of fame he is obviously uncomfortable with.

Notoriously publicity shy, he never gives interviews or is photographed out of character. Mazer, on the other hand, can live his life unrecognised and is at ease talking about how the two of them have ridden this fame trip.

But success has made the Ali G show a busted flush, and Mazer is the first to admit that, unless it targeted crofters in the Outer Hebrides, another series is not viable. "This new show may well be the last,'' he says, adding that after living in each other's pockets writing and filming Da Ali G Show, Ali G Indahouse and Ali G in da USAiii, the two are going their separate ways. "I haven't seen Sacha for three weeks - the longest time in years."

Warm, hairy and welcoming, Mazer lounges, cross-legged, in his Soho office. A ragged beard looks as if it has been nibbled by a hamster and a baseball cap is clamped down on dark, not very clean, hair. He is a good foot shorter than his front man and, despite all the hair, looks younger than his 31 years. But he is engaging, witty, has seemingly endless time to chat and it is not hard to see why his girlfriend, presenter and actress Daisy Donovan, is so smitten.

But it is his 20-year relationship with Baron Cohen that is most intriguing, something he seldom speaks of. "We've spent the past five years together. We know everything about each other - moods, favourite foods, what we will order in a restaurant when we're tired. It's more like a marriage than my relationship with Daisy. But we never talk about money and we never talk about the future. It's difficult and horrible because we were friends first, so we get our agents to talk about all that stuff."

Key to their success has been not jostling for the spotlight. Mazer seems content with his back-room role and quiet life, while Baron Cohen often finds himself the centre of attention. "Sacha is such an overwhelming force, you're always second, always invisible."

But he claims Baron Cohen has paid a price for his celebrity. While he enjoys some of the trappings - he has partied with the likes of Madonna and Naomi Campbell - he loathes other aspects and is intensely private, fiercely guarding his relationship with his fiancee, the former Home and Away star Isla Fisher.

Mazer is just as reluctant to talk about his long-term relationship with Donovan. The couple share a flat in west London, and have worked together on The 11 O'Clock Show and more recently on Daisy's eponymous series, Daisy Daisy.