It has been billed as some sort of rivalrous battle - not least by Lily Allen herself. Speaking recently of her collaboration with New Look, she said: "They have responsible role models and they're very conscious of having positive body images and promoting positive women. Unlike Kate Moss and that f***ing billionaire who's thrown a load of money at her so we get to see what her wardrobe is like." To which there is only one response: meow!

Ever her father Keith's daughter, Allen has been brought up to know the value of a juicy celebrity feud.

Pictures: Lily Loves collection launches at New Look

Gallery: Lilly Allen's New Look collection

It's a surefire way to generate press, and where there is press, sales will surely follow.

For her first collection for Topshop, which had its New York launch at Barneys last night, Moss has taken the best pieces from her wardrobe and tweaked them into items that will sell on a mass market level. For her first collection for New Look, which she launched in Oxford Street last night and which is on sale today, it seems Allen has done much the same. Lily Loves ... New Look is full of the sort of diaphanous balldresses that Allen has made her trademark, such as the Foxtrot, an ankle-length ruffled gown that retails at £55. The priciest piece in the collection, it is still a quarter of the price of the most expensive piece in the Moss Topshop collection, a black leather jacket costing £200.

Of course, when it comes to taking inspiration from your own wardrobe, Moss, a model of almost 20 years' standing, has a far more bulging closet to draw from than Allen. Which is probably why, in the long term, the Moss range will have a wider appeal.

While Moss's £45 f loral tea dress received the most attention at the British launch, it was the £200 black leather jacket which elicited the most interest among older customers. With its leather jackets, kaftans, bikinis and gladiator sandals, Kate Moss Topshop is a far broader offering than Lily Loves ... New Look.

Unfortunately, "broader" does not necessarily mean easier to wear. Where Lily Loves ... probably has the edge is that it caters more readily to the larger woman.

The Gandalf, a printed smock dress costing £28, is a far slouchier, easier dress than any in the Kate Moss collection, and comes in sizes 8-18.

Allen is proud of her size 12 curves. "I'm irritated by the emphasis on being thin. I wouldn't swap bodies with anyone," she has said. It is commendable that she has let this attitude show through in her collection - though since baggy smocks are in fashion this summer, it was hardly a commercial risk to do so.

Since the British market seems to go potty over celebrity high street fashion, there is presumably more than enough room for Moss, Allen and any other celebrities who want to join in.

But women, like fashion, are notoriously fickle, with today's must-have becoming tomorrow's bored-with. After the hype around both collections has died down, the biggest measure of each range's success isn't its pretty dresses, but whether it still exists in five years.