A one-off prototype was worn by 16-year-old Chloe Green, daughter of Arcadia owner Sir Philip, at the Kate Moss Topshop launch party last month - much to the consternation of Moss's VIP friends, who had been hoping to bag it on the night.

Kate with Topshop boss Philip Green and daughter Chloe in a prototype of the garment
At that time, Moss was not quite happy with its design, so it was sent away to be modified before going into full production.

Those who don't manage to snap up the dress before it sells out won't have too long to wait until the collection is added to once again.

The next instalment, a full autumn/winter collection, is due in store at the end of August and promises to move away from signature skinny jeans and focus more strongly on dresses.

A ￡45 pansy print romper dress has so far proved the fastest-selling item so presumably Moss and Topshop want to capitalise on the success.

While the first collection was well received in general, it was criticised in some quarters for being nothing more than a "greatest hits" of key looks from Moss's own wardrobe.

Insiders say the autumn/winter collection will reveal more of her talent as a designer.

"Kate is getting really into it. Now that the angst of the launch is over, she feels really focused," said a spokeswoman for Topshop.

"Fans can definitely expect something more purist - she's ready to push the collection to another level."

To help Moss's muse and his profits flourish, Sir Philip has given the model a new office at Topshop HQ. The summer collection is available from today.