Cheryl Cole has angered her Girls Aloud bandmates by taking on the role as X Factor judge.

The singer, who turns 25 later this month, was revealed as Sharon Osbourne's replacement on the ITV talent show last week, joining Simon Cowell, Louis Walsh and Dannii Minogue on the judging panel.

The X Factor job comes on the hot on the heels of Cheryl's solo work with The Black Eyed Peas rapper Will.I.Am on his hit single Heartbreaker.

Together with her high-profile marriage to Chelsea footballer Ashley Cole, Cheryl's professional and private life is overshadowing her bandmates.

Rivalry: Has 'Life got Cold' for the Girls Aloud bandmates?

Sources close to the manufactured five-piece, who found fame on Popstars: The Rivals in December 2002, told Heat magazine that Nadine Coyle and Sarah Harding  are especially finding it hard watching Cheryl receive all the attention.

A source close to Northern Irish Nadine tells the magazine: 'The other girls are very put out that Cheryl has landed the judging role.

'They knew she really wanted it, but some of them found the news hard to handle, especially Nadine.

'At the end of the day, all the girls are talented, but Nadine has got the best voice and as it's a singing contest she should be the one for the job.'

New line-up: Cheryl Cole has the X Factor alongside fellow judges Louis Walsh, Simon Cowell, Dannii Minogue (front) and hosts Dermot O'Leary and Holly Willoughby (back)

Meanwhile, Sarah, 26, is said to be put out by Cheryl's appointment because she sees her future in TV once the band ends.

A friend of Sarah's said: 'Sarah and Cheryl both wanted to get into TV, but it seems Cheryl is moving closer to that before her.

'Sarah booked a magazine deal with her boyfriend Tom (Crane) when Ashley and Cheryl were all over the press and now she's really envious of Cheryl's X Factor deal.

'It's getting really competitive. Sarah always thought that she'd be the TV girl in the group, not Cheryl.'

Cheryl's appointment as X Factor judge comes at a challenging time for the group.

After the completion of their recent UK tour, Girls Aloud are hoping to return to the studio this summer to record their fifth studio album, a follow up to last year's Tangled Up.

Cheryl's role on X Factor will require her to attend long, gruelling auditions up and down the country, as well as appear on live Saturday night shows once X Factor debuts in August and runs until December.