Jemima Lewis: Are you dreaming of a black Christmas?

Is it me, or is Christmas looking a bit sombre this year? There's a lack of jollity on the high street

I haven't even got my tinsel down from the attic, and already I've blown it. This year, you see, there's only one kind of Christmas tree worth decorating - and it's black. The funereal look is apparently the "surprise phenomenon of 2005" - so surprising, in fact, that John Lewis has already sold out of its entire stock of £90 pre-lit black trees.

Still, there are other ways to bring some yuletide gloom into your home. You could follow the advice of Habitat's style experts, and "paint a wall in your house black and line your fairy lights up vertically or horizontally". Or you could enforce a monochrome theme throughout.

"If you want to do an elegant, sophisticated Christmas," explains Susan George, editor of Ideal Home magazine, "black is the way to do it. It's a look that fits with all our pale and minimal homes where traditional reds, golds and greens are going to stick out like a sore thumb."

Is it just me, or is Christmas looking a bit sombre this year? It's not merely a question of interior decor - although I must admit I prefer a bit of spangly red and gold myself. It's more a feeling in the air: a sullenness, a mood of existential rebellion against Christmas itself.

Certainly, there's a distinct lack of jollity on the high street. November is usually a time of seasonal joy for Britain's retailers, but this year the malls are empty. Last month's retail figures were, according to the Confederation for British Industry, the worst for 22 years.

In part, this is just a symptom of Britain's economic hangover. Throughout 2003 and 2004, the nation indulged in a record-breaking orgy of consumer excess - and now we are paying the price. Weighed down by credit card debts, many households are struggling to cope with rising mortgage repayments, council tax and utility bills. It's hard to summon up much interest in the perfect stocking filler while the bailiffs are banging at the door.

But it isn't merely a matter of tightening the purse strings. In fact, there is one retail area that is flourishing: that of "ethical giving". Oxfam Unwrapped and the catalogue company Good Gifts have both experienced a huge surge in interest this year. British consumers may be tired of shopping for their loved ones, but it seems that they quite like the idea of buying a goat for a Somali farmer, or a lavatory for an entire African village. These schemes kill both birds with one stone: the farmer gets his goat, and the loved one gets a thank-you card instead of a present.

Doing some grudging Christmas shopping on the internet this week, I broke off to have a look at the Good Gifts website. Straight away, I found two things I genuinely wanted to buy: an Old Dog's Retirement (£15), which pays for "three unhurried months in a rest home for weary pooches"; and a £25 Christmas Hamper, "rammed with necessities and seasonal treats for elderly people who may receive no other gifts".

I am a sucker for animals and old folk; and as I tapped in my credit card details, my eyes filled with tears of pious self-satisfaction. Now that's what I call giving.

Unfortunately, I'm not sure it's what my friends would call receiving. They might not want - let alone need - any more trinkets, gadgets and gew-gaws in their lives, but they would miss the presents under the tree if they weren't there. The Christmas tradition of frenzied unwrapping has been hard-wired into all our brains. We are trapped by a festive obligation to buy and be bought for.

You have to hand it to big businesses: they know a thing or two about brainwashing. Over the decades retailers have steadily increased the lead-time up to Christmas, predicting that the longer we were exposed to twinkling lights, Bing Crosby and fake snow, the more deranged (and extravagant) our shopping habits would become.

Perusing the Sunday supplements last weekend, I found a magazine spread of "must-have" gifts for men. These included a strikingly horrible snakeskin umbrella stand (£225), a "gentleman's accessory box" containing a bottle of Courvoisier (£4,100) and - most baffling of all - a "Krug champagne drinks trunk" (£29,000 by appointment at Harrods) containing three bottles of bubbly and a slot for an ice bucket. For that much, you could buy your own vineyard.

Is it any wonder the high streets are empty? If a Krug trunk is a must-have, that makes virtually all of us have-nots. Christmas has gone from being a festival of desiccated fowl, snoring relatives and brightly coloured socks to a competitive style event: one in which only the insanely rich - and tastefully monochrome - win prizes.

Sooner or later the shoppers will return: they have no choice. But I predict they will wait until the last minute, when retailers lose their nerve and start slashing prices. Big business may have messed with our heads and turned Christmas into feel-bad event; but the consumer is not beyond exacting a little vengeance.