Some of the books shortlisted for the Costa Book Awards. Picture: Graeme Robertson

Nineteen Ninety Nine was a good year for me. Along with some other gongs (I mean the prizes, not the writers), I won a Whitbread Award for my first novel The Last King of Scotland. It was an honour at the time, and has been since; but if it happened to me now, I'm not sure I'd want the award to be mentioned on my book jackets.

Why? Because it's now called a Costa Book Award. Last year Whitbread, parent company of the Costa coffee chain, decided that, as it didn't sell goods branded Whitbread any more, there was more value in focusing the sponsorship on a particular product and service.

Established in 1971, the Whitbread Book Awards honoured the prime of contemporary literature. Previous winners include Seamus Heaney, Salman Rushdie, Ted Hughes, JK Rowling, Kazuo Ishiguro and Ian McEwan. Costa has continued in this vein: look out, among this years' contenders, for William Boyd (novel) and, more out of left field, John Haynes (poetry). I'm sure whoever is chosen will welcome their accolades when announced tonight and their cheques but will they, I wonder, be quite so keen on the brand-sullying taint of "Costa"?

Yet there is some sense in the move, from Whitbread's point of view anyway. While customers at Costa's 500 stores countrywide might not all be avid readers, there has long been an association between coffee and reading (you could say modern literature was born in the coffeehouses of 18th century London), one already exploited by Borders and Starbucks in conjunction, and by Waterstone's with its cafe developments. It has also been argued that coffee has been one of the "driving forces" of civilization itself, as if it speeded up linkages between different phenomena and cultures.

All that is very well, but I still wouldn't want Costa on my book. Costa just doesn't cut it for me as a signifier. I know it's Costa as in Costa Rica but it sounds a little low-rent. Frankly, even Starbucks would have more of a ring to it, being closer to an idea of literary value than Costa is.

It's hard to put one's finger on why Whitbread was semiotically successful and Costa isn't. It has to do with the penumbra of connotation around a word, which is largely governed by history and context. You can see how delicate it all is when Whitbread becomes Whitebread - something entirely different. In an American magazine I once, through a spelling error, became winner of a Whitebread. This lauding of my bland vacuity has always stood me in good stead in that country.

Part of the problem with Costa is the lack of grandeur. In 2001 I was a member of the final judging panel of the Whitbreads. It was amazing to wander round the Brewery, the labyrinthine Whitbread headquarters in Chiswell Street in the City. Founded in 1742 by the first Samuel Whitbread, the Whitbread brewing family was a chain of value in its own terms, one which one was happy for one's book to be associated with. Not because of brewing per se but because they were stylish, radical philanthropists who put their millions to good use, establishing poor schools, funding the Drury Lane Theatre, and doing the first systematic weather observations in Britain.

The second Samuel Whitbread was so radical a reformer he was hissed at by rightwingers in parliament. He became so depressed by the state of the nation that on June 6 1815, he committed suicide by cutting his throat with a razor.

The company that the Whitbreads developed is now a plc - owner, as well as Costa, of such brands as the Premier Travel Inns, Brewers Fayre, TGI Fridays and Beefeater: not the gin, alas, but the restaurants.

It all seems something of a comedown, with not a jot of radicalism or style to be found among the lot of them. But I suppose that is what happens when you sell the family silver. I rather suspect the Whitbread board and the award organizers have done the same with these awards. Maybe it's just another case of tempus edax rerum, or "time, the devourer of all things", as Ovid once said in a nice little coffee shop on the shores of the Black Sea.