Kate to wed in Topshop dress

Katy, who's married to Kate's best pal rocker Bobby Gillespie, has been helping the model design her new clothes range, which will hit stores on 1 May.

Through this she's become very close to the Topshop team and we're told they love working together and are "absolutely delighted" to be designing a dress for Moss.

Pete Doherty, 28, recently made their engagement official by referring to Kate as his "fiancée" on stage at the Hackney Empire.

Kate had lifted her "no wedding talk" ban on the Babyshambles frontman and the couple are now actively planning their big day.

Of course, no woman's wedding day is complete without the perfect dress, and who else would you trust to provide you with such a thing other than your best pal — especially when she's a designer who works with the likes of McQueen.

A close friend tells us: "Katy is tered that Kate trusts her enough to make the perfect dress, it's every designer's dream. She asked her very recently to do the honours and they are currently going through ideas together.

"Katy will work on the dress with the Topshop team she's met while helping Kate out with her new range.

"Kate really wants a low-key dress, something simple and elegant. The whole wedding will be a low-key affair so it makes sense to have a non-fussy yet funky dress.

"Kate is a big fan of her friend's designs and Katy's helped her out a lot designing this new Topshop range so she thought what better way to repay her than to have her design the wedding gown."

Last July, Kate, 33, did a reading at Katy's wedding to the Primal Scream frontman and reportedly told guests: "It's going to be me next."

Meanwhile, Moss has come under fire from US critics who have branded her £3 million Topshop range "dull".

The 80-piece collection is eagerly awaited by punters and fashionistas alike.

But Barneys creative director Simon Doonan got personal, saying: "She is not a high-born girl. She's a working class slag from a crap town."