We reported last week how Nathan has performed on the same bill as both N-Dubz and JLS, prompting us to ask if it was fair he was in the competition.
The Daily Star Sunday however has taking it a step further, suggesting that Nathan's close links to Tulisa could lead to favouritism if he makes the live shows.
A show insider told the newspaper: “It’s shocking to think someone who has worked alongside one of the judges is allowed to compete.
“It hasn’t been mentioned on the show that they even know each other. Other singers who weren’t given the chance to sing at judges’ houses will be left pretty fed up.”
Speaking after last night's judges' houses performance, the insider added: “A lot of people will be wondering if Nathan was guaranteed to go through just because he has got Tulisa on his side.”
But last night an X Factor spokesperson insisted to to the newspaper: “As soon as Nathan stepped on stage Tulisa acknowledged that she knew him.
“The other three judges voted first and gave him a yes, so he would have gone through regardless of Tulisa’s final vote.”