Fashion: 'Twas the knit before Christmas...

Seasonal sweaters have shaken off their comedy image to become really rather stylish – and there's even a charity day devoted to wearing them. It's enough to make you jumper for joy

There can be few items of clothing as fashion-backward as the Christmas jumper, the knitted equivalent of "Jingle Bells" sung badly by a Scout group in a provincial shopping centre. And yet, from the daft to the designer, we can't get enough of the sort of sweaters that earned a scornful diary entry from Bridget Jones (remember Colin Firth's reindeer?).

Friday next week is Christmas Jumper Day, when Save the Children permits us to don seasonal kitsch in exchange for a donation to the charity, which also offers knitting patterns for DIY jumper fans (lock up your granny). The newsreader Jon Snow and the actress Ashley Jensen are among the campaign's celebrity recruits.

But irony or charity isn't required for those seeking to channel Cliff Huxtable, of Cosby Show fame, or George Michael in Wham!'s "Last Christmas". Sarah Lund, The Killing's toasty television detective, is credited with popularising Faroese sweaters and their Scottish Fair Isle counterparts. In the age of novelty and nostalgia, it's perhaps a natural evolution for our knits to grow snowflakes and Santas.

And so we have The Wanted, the boy band, frolicking around a tree in Esquire wearing a range of jumpers including Nathan's green wool reindeer print from Gant (£135). High-street and online stores have increased their range of festive sweaters this year at both ends of the market, and report snowballing sales as Britain freezes. At Asos, sales of novelty and Fair Isle styles have "exceeded expectations", increasing more than five times on last year, while Jeremy Langmead, editor-in-chief at Mr Porter, says the "rustic, retro charm" of sweaters there is boosting sales by similar amounts. Net-A-Porter has its own department for designer offerings including a bauble-covered red jumper by Meadham Kirchhoff for £945, a £396 white Moschino reindeer number, and a £355 top from Tibi that features a giant penguin. For a cheaper take on the trend, try Topman (£38).

An American trend for "ugly Christmas sweater parties", meanwhile, has taken off here, creating a market for presumably single-use jumpers. Matthew Lake, 21, a web entrepreneur from Shropshire, has already sold almost 1,000 sweaters since he launched the pleasingly lo-fi DaftChristmasJumpers.co.uk in October. He's struggling to meet demand for his range of almost 50 knits (top seller: a top that looks like a Santa jacket). His theory of the Christmas jumper's new popularity in times that are cold and bleak is simple: "They're just plain old good fun."