Lily Allen wouldn't be Lily Allen if she kept her opinions to herself - and she was on vintage form last night as she watched the X Factor semi-final.

Surprised by Fleur East's selection of a song which has only had a digital release so far, the Sheezus star took to Twitter to talk about "music industry corruption".

The 29-year-old was surprised to hear Fleur singing Mark Ronson's Uptown Funk - a Bruno Mars collab which we recently told you had hit the web in audio form.

She wrote: "Is this even out yet? #XFactor ... Well done to @sony for managing to get a not yet released song of theirs sung on prime time weekend telly. #uptownfunk #shazam #airplay

"It is an amazing song and Fleur did it justice but it's still a great example of music industry corruption. #uptown funk"

The song was made available as a digital download on 10 November, but will be on Ronson's forthcoming Uptown Special album - which is due for release next year.

When a Twitter user accused Lily of being "bitter", she responded: "How so when I'm giving props to all the artists involved."

However she later appeared to have deleted one or two of her tweets.

Is this even out yet ? #XFactor

— lily (@lilyallen) December 6, 2014

Meanwhile The Mirror reports that judges Cheryl Fernandez-Versini and Mel B are "at war" after their on-screen spat last weekend.

A source said: "Suddenly they're like two prize fighters staring each other out before a fight.

"Neither of them has made any effort whatsoever to make things up and it has driven a wedge down the centre of the team with different people backing Cheryl or Mel.

"In the past the judges have been seen regularly wandering between each other's dressing rooms, chatting away happily and hanging out after the show.

"At the moment all that has come to an end. The rival sides have been locked away behind closed doors and any contact at all is very cold and short.

"It's not a warm environment to be around."

Oh dear.