Simon Cowell tells Cheryl Cole Dannii's winning The X Factor style war

Cheryl isn't confident about her look

Cheryl is starting to feel the strain after a tough week

Cheryl Cole's best friend Simon has been winding her up over her clothes onThe X Factor, pointing out that rivalDannii Minogue's winning the fashion war this year.

Cheeky Simon's going out of his way to coo over Dannii's outfits while teasingCheryl, 27, about hers.

‘He'll say: "Well, Dannii's got it right again, unlike you Cheryl!"' a show insider tells Now. ‘He's even calling her a sexed-up prom queen!

‘He's only having a bit of fun but with everything else that's going on it's starting to get to her, which is why she's changed to wearing more neutral colours and conservative dresses.

'Cheryl takes a lot of pride in her appearance and has stayed loyal to her original Girls Aloud stylist Victoria Adcock.

'She's become a good friend, so Cheryl takes Simon's comments really quite personally.'

To read the full story about Cheryl Cole, see Now magazine dated 29 November - out now!