What it's like to party with the Booker crowd

It was the best of times and the worst of times - the best if you were a 59-year-old Irishman from Wexford with a slightly chilly reputation and a talent for sensuous prose cadences; the worst if you were a 59-year-old Englishman from Leicester with a suavely charming reputation and a talent for mixing up fiction and fact to sparkling effect. The former, John Banville, won the Man Booker Prize on Monday, the culmination of the most exciting year for fiction since the award started 26 years ago; the latter, Julian Barnes, had to go home with just a runner's-up cheque for £2,500, despite having been the bookies' favourite since the announcement of the long list of contenders in August.

For both men, and for the assembled ranks of authors, publishers, agents, TV people, literary editors and newspaper diarists, it was one of the longest days of the year. For the judges it began at 1.30pm when they met to choose the winner (from the shortlist of six) over a three-hour lunch at the Clerkenwell home of Lindsay Duguid, fiction editor of the TLS. Rick Gekoski, the rare-book dealer, proposed they each speak up for their favourite book. He chose Banville's The Sea, which he regards as "up there in the context of high modernism with TS Eliot, Joyce, Nabokov, Wallace Stevens". Others spoke for Zadie Smith's On Beauty and Kazuo Ishiguro's Never Let Me Go. The other three books (Ali Smith's The Accidental, Sebastian Barry's A Long Long Way and Julian Barnes's Arthur & George) elicited less passion. As lunch gave way to teatime, it became clear this would be a two-horse final between Banville and Ishiguro. Zadie Smith hadn't made the final shootout. "I loved reading her," says Gekoski, "but the book read like a promising first draft of something that didn't quite come to fruition." The chairman, Professor John Sutherland, became a figure of controversy when he chaired the prize in 1999 and leaked reports on the judging process. This year, he was on best behaviour. Contrary to reports, he did not win the Booker for Banville on a casting vote. "He voted as a judge, not a chairman," said Gekoski. "He voted at the end, after he'd heard the arguments from the four other judges."

By the time the judges went home, to climb into tuxedos and sequinned frocks, the winner was blissfully unaware of his fate. Currently teaching literature in Philadelphia, he had flown in from New York, with no hope of winning, and was booked on a plane back next day to pick up an honorary doctorate from Skidmore University in New York State.

Across London, the publishers Cape, Faber & Faber, Penguin and Picador were going into Booker overdrive. Publicity departments were split in two - one half to accompany their finalist to the Guildhall dinner, the other to host the late-night parties that have become traditional for both winners and losers.

The champagne reception at the Guildhall began at 6pm. Previous prize winners (AS Byatt, Ben Okri) and former judges (John Carey, Lisa Jardine, Kenneth Baker) rubbed shoulders with ambassadors, politicians, actresses, broadcasters and the odd rock guitarist. Dinner was tuna carpaccio, pheasant and chocolate pudding.

The winner was revealed to selected literary journalists at 6.10pm (to enable them to get their stories into the first editions) but the other diners had to wait until 10.30pm to hear the announcement made - somewhat detachedly, like a lawyer reading a will - by Professor Sutherland. "[The judges] have agreed to award the Man Booker prize to John Banville's The Sea."

In the minstrel's gallery, Kirsty Wark from BBC2's Newsnight fronted the TV coverage and sought the opinions of three literary editors, Jan Dalley, Suzi Feay and Robert McCrum.

After, everyone piled across London to Soho, where the after-show parties had been underway since 9pm. Seasoned literary liggers who weren't invited to the Booker dinner knew the order in which to go. Start with the Faber party (publishers of Sebastian Barry and Kazuo Ishiguro) at the Union Club because they have the best canapés, and move on to the Cape party (for Julian Barnes) at Soho House. When - horrors! - Barnes was denied the prize, they departed, like bats from Hades, and made for The Groucho, where the Picador party for Banville was yards from the Penguin thrash for Ali and Zadie Smith.

By 11.30pm, when Banville arrived to loud cheers, The Groucho Club was heaving. Despite Zadie Smith being the book world's current darling, her party was apparently "blowing tumbleweeds" according to one reveller. It would seem that everyone prefers a winner.