But together with their friend Zita Lloyd, the models have managed to coax an unprecedented display of generosity from the fashion world. The cause? Their charity Clothesline, which offers help to Africans affected by HIV and Aids.

Take the picture on the right (in the print edition of the Style magazine) — called Fairies, it is by Rankin, and he has donated it for the girls’ forthcoming charity auction (Style readers can bid for it; just email rankincomp@sunday-times.co.uk). Others who have given their works include Damien Hirst, David Bailey, Mario Testino, Steven Meisel and Gilbert and George. And the quality of the donations is pretty spectacular. “Far from them giving us their inferior pieces, it’s what we hoped for and beyond,” gushes Guinness. So, there is a portrait of Kate Moss by Craig McDean, a painting of a tiger’s head by Ronnie Wood and a photographic sketch by Helena Christensen.

“It’s staggering how giving people have been — incredibly glamorous people who you wouldn’t expect would want to get involved. It’s given me great faith in human nature. But then we choose very carefully. We only ask nice people,” says Guinness.

Nice people? Well, if you want to bid for anything other than Rankin’s picture, then you have to be invited to the Clothesline event. So you need to be someone who is known for their generosity — the billionaire Philip Green, for example — or part of the models’ fashion crowd.

The event takes place next week, during London Fashion Week, at Paul Allen and Dave Stewart’s arts club, The Hospital. “A live auction of 70 prints would ask too much of people’s attention spans,” says Parfitt. “So it’s a silent one. People can just come, make a bid and go. There’ll be plenty of drink to get people in the mood. It’s exciting that people will be able to buy from artists who don’t normally choose to sell.” Whatever isn’t bought will then be open to the public to view and bid for.

This will be something of an improvement on the girls’ event last year — a catwalk auction of 60 outfits by the likes of Westwood, Galliano and Cavalli. Although there were plenty of gestures (Jodie Kidd’s husband, Aidan Butler, bought everything she had modelled; Erin O’Connor bid for her own dress when she realised it wasn’t selling), as soon as the show was over, the front row got up and left without buying a thing. All heart, the fashion crowd.

“It was a shame,” says Parfitt, “but we ran late, so we understood.”

Of course, Clothesline is not the first fashion charity, nor are the girls the first “model citizens”. “Lots of models do charity work, but we don’t just put our names to it. We are 100% involved,” says Parfitt. “We do all the legwork, calling in every favour we have earned from the industry.”

The idea was conceived five years ago, when Guinness was living with Parfitt in New York, after the two read a newspaper report about the Aids epidemic in Africa. Guinness pulled in the third Clothesline member,

Lloyd, who now works for Bob Geldof and Bono’s pressure group Data. “She’s our facts-and-figures girl. She knows a lot about the situation in Africa,” says Guinness.

Have Parfitt and Guinness been to Africa? “Not properly,” says Parfitt. “Every time we plan to go, I get pregnant,” adds Guinness. “I leave the aid work to people who know what they’re doing. We’re good at raising money.”

Sacrifices are readily made. For example, Parfitt will be too busy with Clothesline to work at New York Fashion Week this season. But the hardest aspect, she says, is “the process of pestering. It never takes one call, it takes about eight or nine”.

“There haven’t been many disappointments,” adds Guinness. “But if your expectations aren’t sky high, you can only be pleased with what you get. We’re not Elton John — we’re not expecting to make millions.”

The remaining artworks will be on display and open for bids at The Hospital, Endell Street, WC1, from September 20 to 24; www.clothesline.org.uk

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