Clive James is unwell.

How unwell is not entirely clear. A year or so ago, rumours of his demise were so virulent that he was forced to echo Mark Twain and deny that he was in life's departure lounge. Having said that, there's no doubting that the 73-year-old is not in peak condition. A couple of times lately, he's given cause for serious concern. Among other maladies, he has emphysema and a wracking cough. Added to which, as he told one journalist, he has "all kinds of little carcinomas" and "leukaemia is lurking".

Proximity to a hospital is therefore vital, which is why he is living in Cambridge, giving him ready access to Addenbrooke's, which he must visit regularly. When I ask how he's keeping, however, he doesn't sound as if he's about to board the next flight to Parnassus quite yet. "I'm not quite as frail as some journalists tend to suggest," he quips, "but I can't blame them. I must look pretty weak."

Because of the state of his health, this interview was conducted via email. Even then, though, says James, it left him feeling exhausted, adding: "There's so much to say on every topic, and so little time."

The topic at the top of his agenda at present is Dante's Divine Comedy, which he has translated. It is a monumental achievement, the culmination of decades of reading and thinking, combining formidable scholarship and poetic inventiveness and testing his talent to the limit.

He had always found previous translations of the Italian classic unsatisfactory, whole chunks of which were too dull to read. Thus the task embraced by him was scarily daunting.

"There are scads of Dante translations whether in prose or verse, but I usually found that they got less interesting about a third of the way through," he acknowledges. "They made Hell seem more intense than Purgatory or Heaven. But for Dante all three regions are exciting, and for the translator the heart of the job is to bring the later parts of the poem poetically alive. Almost any poet can do something with those hellish centaurs who guard the river of blood and make sure nobody gets out. But to bring out the architectural beauty of the upper regions of Heaven really takes some technique, and I suppose I think that what I've got to offer is a whole lifetime of learning to make words beautiful."

It is a reminder, were one needed, that James is first, foremost and forever a writer. In the minds of the majority of the non-reading public, however, he will always be remembered as a television personality, in which guise he is culpable for bringing to our screens Margarita Pracatan, the excruciating Cuban singer, and "highlights" from the Japanese game show Endurance, on which the contestants were hung upside down in the Egyptian desert while hot sand was poured over them, after which they were force-fed soft-boiled sheep's brains. How we laughed, complacently secure it could never happen here...

James himself regards his time in television as a by-product of his writing career. He may not have been the first reviewer of TV but he was the one against whom all others came to be measured. I have always cherished his description of the ice skaters, Torvill and Dean, in their gold costumes, "looking like two packets of Benson & Hedges cigarettes in a refrigerator".

His metamorphosis from critic to performer was not, he says, such a seismic shift as many people believed. From his perspective, everything he's done has its roots in writing. "On my television show, even when I was improvising, I was still writing in my head just before I said it."

He was always wary, too, of how seductive television can be. It is, he says, "an all-consuming job but when you're caught up in the excitement and the fame, it's very easy to forget that one of the things it's consuming is your soul." From Dick Cavett, the American chat show host, James learned that while television can be rewarding in every sense, it is important to have other things in your life.

It was around the turn of the millennium that he moved himself off television to concentrate on writing. Doing nothing was never really an option. "In my family," he says, "I am famous for spending the whole summer holiday crouched over my notebook at the cafe while everybody else is on the beach." That he is industrious is an understatement. It was the New Yorker which famously called him "a brilliant bunch of guys". To date he has written six volumes of autobiography, four novels, copious amounts of poetry and innumerable essays.

It is the latter which many people regard as his finest work. His imprint is indelible, an intoxicating cocktail of wit, acerbity, insight and irreverence, all of which makes him a parodist's dream. "If the style is less tortuous than usual," he wrote of Karl Miller, "the stylist is even more tortured."

"He is a dandy," he opined of his fellow Australian, Barry Humphries, "who has studied Europe's history of style more intensely than any of its own dandies."

In such sentences you can hear James's true voice, which has never fully lost its sardonic and abrasive antipodean edge. He is the kind of guy who calls a dingo a dingo. He was born in 1939 - the other big event of which (as he remarked in his first volume of memoirs) was the outbreak of the second world war - in Kogarah, a suburb of Sydney. Twenty-three years later he fled to London, part of an exodus that included the art critic Robert Hughes and Germaine Greer who, in his memoirs, he renamed Romaine Rand because "one could not attribute bad language to a living woman".

Britain was the making of him. He went up to Cambridge where he studiously neglected his studies and applied himself to having a whale of a time, like his hero Byron. As befits one who had been playing the clown throughout his childhood, he joined the Footlights and made the first of his many pilgrimages to the Fringe. "I treated Edinburgh as if it were at my feet," he once wrote. "Actually I was at its. The strict romance of the city had found a suitably compliant devotee."

Thereafter London called. It was the era when Martin Amis, Ian McEwan and Julian Barnes were beginning to make their names. At the Pillars of Hercules pub in Soho, de facto office for the New Review, James met its editor, the chain-smoking, hard-drinking, effortlessly caustic, casually charismatic Ian Hamilton, and soon became part of the clique around him.

It was the 1970s, when London could still claim to have a literary core. James wrote on television for the Observer, literature for the Times Literary Supplement and the New York Review of Books, and on Norman Mailer's biography of Marilyn Monroe for Commentary. "Mailer's adoration is as amateurish as an autograph hunter's," he wrote, which, when I read it again recently, struck me as similar to the adoration which James himself exuded for Princess Diana. "She wasn't just beautiful," he wrote on her death. "She was like the sun coming up: coming up giggling. She was giggling as if she had just remembered something funny."

Recalling this, would he have been interested in being Poet Laureate? "The ... job has been made too hard by Andrew Motion's selfless dedication to the task. Carol Ann Duffy can do that too, but I would have been too lazy. I had my eye on the Oxford Poetry Professorship, but I suppose that by now it's too late."

Did writing his own poems help him get into Dante's mindset? "My own epics were meant to be comic and were written ages ago. Nor is the Divine Comedy comic in any way: on the contrary, it's a very serious business, even though it's basically a page-turning thriller. But he can be sardonic, especially when abusing the latest pope; and I suppose my experience with satirical epics helped a bit in that department."

Dante is credited with giving the Italians their language: to what extent does he believe that to be the case? "My wife Prue Shaw's book about Dante, which will come out in America next February, brilliantly explains how Dante combined a whole range of dialects to produce, in the Divine Comedy, a synthesis which we now know as the Italian language. Often known locally as la bella lingua (the beautiful language), it has one conspicuous drawback: it can make any Italian sound like a poet. Dante's greatest quality is how tough he can be in a language which so easily turns to cheap music."

Thus speaks the great autodidact. James may have been an indolent student but he has more than made up for that since. He hungers after culture the way some do junk food. "There was never a time like now to be a lover of the arts," he writes in Cultural Amnesia, which comprises more than than 900 essays on people who shaped the 20th century and which, he says, was "meant to be only a sketch of a much more complete book". Ideally, he would like to write a second or third volume. "But there again, I feel short of time. I honestly thought I would never live to see my Divine Comedy translation edited and published."

Dante: The Divine Comedy, translated by Clive James, is published by Picador at £25