Last night NBC announced they were adding a Wednesday instalment of 'The Voice' meaning it will clash with The X Factor USA which airs on the same day. Previously The Voice was to air on Monday and Tuesday with The X Factor on Wednesday and Thursday.

The premiere of The X Factor on September 12th will now be up against The Voice which would have already gained a following throughout that week.

Simon is naturally furious with NBC and spoke exclusively to TMZ last night saying he thought he had a "gentleman's agreement" with NBC ... that "The Voice" would run Mondays and Tuesdays, and "X Factor" would run Wednesdays and Thursdays on FOX ... so fans could watch both.

Simon says NBC is turning on its own audience, forcing them to choose between Christina Aguilera's show and Britney Spears' new show.  And speaking of them, Simon says, "Britney's not going to appreciate the fact that Christina -- who has been a bit of a rival -- isn't allowing Britney to have a night of her own."

Simon tells TMZ, he believes the move is as personal as it gets, because "The Voice" came to England and went head-to-head with Simon's show, "Britain's Got Talent" and got its ass kicked.

Simon says, "These guys have really got it in for us.  It's nothing short of dirty tricks."

Cowell adds, "The reason they've done this is they don't want people to see 'X Factor' because they've heard how good the series is.  They don't want their audience to see Britney Spears.  They don't want their audience to see Demi Lovato."

Simon says he doesn't think Britney knows yet, but when she finds out "She's going to be devastated because she's put her heart and soul into this."

As for Simon, he says he's not scared, adding, "I can't bear it that the network is playing political games and playing with the audience."

The Voice also went up against Britain's Got Talent for the first time in the UK this year. Although starting strongly they came crashing down when Britain's Got Talent thrashed them in the ratings during the live shows.

SOURCE: TMZ

The X Factor USA Premieres on September 12th on Fox.

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