Warring X Factor UK judges Cheryl Cole and Louis Walsh are said to be barely speaking off camera.
The pair are said to be "barely speaking" after repeated clashes both on and off the camera.
The Sun newspaper reports that the crew are now having to work around their rivalry to ensure that they stay apart when not filming together.
“The atmosphere has become toxic — she hates him with a real passion and it shows," a source claimed to the newspaper today.
They continued: “It’s no secret that Cheryl didn’t want Louis on the panel, but since then he has been lording his victory and takes every opportunity to knock her.
“On the panel he has repeatedly slapped her down, and she has given him some poisonous stares in return.
“If looks could kill, Louis would be a dead man.”
Speaking earlier this year, before the panel had been confirmed, X Factor boss Simon Cowell admitted that Cheryl was 'dead against' Louis coming back for an eleventh series.
And when he did return, Cheryl reportedly refused to sit next to him on the panel and confessed things were rather "frosty" between the two.
Now after repeated clashes during the arena auditions and bootcamp, Cheryl is even refusing to be in the same room as Louis.
The supposed X Factor insider claimed; “They made Dannii Minogue and Sharon Osbourne look like best pals.
This is a pressure cooker and it’s only a matter of time before someone explodes.”
The X Factor will kick off later this month on ITV.