X Factor's Grace Davies has become a diva with an 'attitude' and acts like she has already won

X Factor favourite Grace Davies has become a bit of a backstage diva on the ITV singing contest series, according to reports.

The 20-year-old singer-songwriter has not won any fans among the cast and crew of the show, as it seems her popularity may have already got to her head.

The former warehouse assistant from the Lancashire village of Langho, near Blackburn, has enjoyed the first taste of musical success by having one of her original songs in the iTunes top 10 last month, winning the public vote on the opening live show.

But an X Factor source told The Mirror: "Grace acts like she has already won and is a big star.

"All her manners seem to have gone and since winning the opening week she has developed a bit of an attitude. It needs to stop."

Davies – who is being mentored by Sharon Osbourne – was overshadowed last weekend by boy band Rak-Su and winner of the week Kevin Davy White.

It is suggested that the stress of no longer being at the top spot may have taken its toll on Davies, with the hopeful apparently being rude and speaking down to production staff.

"She is not doing herself any favours. No one young in the music industry needs a reputation for being a diva. Sharon is her mentor and she is always very kind to the cast and crew so who knows where Grace is getting this from," the source added.

A rumour was circulating that Davies had enjoyed a fling with singer Matt Linnen, 28, in the X Factor house, though she is thought to be concentrating on this weekend – which involves four evictions in the show's most ruthless week ever.

A source close to the talented star defended her behaviour as a result of her desire to succeed in the process.

They said: "After years of performing in clubs and bars with little recognition, Grace hopes that this is her time for a big break in the music industry.

"This matters so much and she is beside herself that people may mistake her need to be a perfectionist as being difficult. The reality is she's worked so hard for this and is taking the competition very seriously."

Davies is hungry for her big break in the music industry after writing her own material for several years – with her website describing her style as having a "quirky individuality, which perfectly reflects her down-to-earth personality".

The Northerner is influenced by other artists including Ed Sheeran, Emeli Sande and Mumford & Sons. She has yet to comment on the recent claims.