Charlie told us: "If you're not a musician you can't tell the difference between their techniques. Union J sing in unison and it's very simple for a boy band to all the sing the same thing."
"With District 3, they have very intense harmonies and it's really impressive. Union J need to step up I think."
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Charlie then told us that the rivalry between the two bands only really existed on one side.
She explained: "There is a rivalry from one side and not from the other. I feel that District 3 are such cool guys, they are very chilled out and like 'what will be will be'. They're the younger guys so you'd think they'd feel more threatened but to be honest it's Union J."
"They're a bit intense. They need to chill out. They are just a bit too extreme about it and should start focusing on the music."
She added: "At the end of the day, District 3 have incredible harmonies, they have incredible talent on stage and it shows a lot more."
We think it's safe to say that MK1 are firmly team District 3.
On their exit from the show last night, rapper Sim told us that although they were disappointed to be out of the show, they were proud of what they had achieved.
He said: "It's disheartening but at the same time we've got some many good things to take away from going into the X Factor as a two piece urban act."
"It's never been seen before so get through three weeks is amazing achievement."