The Syco boss left the X Factor panel in 2010 to launch the show's US counterpart, which has underwhelmed in the ratings throughout its first two seasons.
© ITV
© ITV / Thames/Syco
Cowell was seen assigning current UK judges Gary Barlow, Tulisa Contostavlos, Louis Walsh and Nicole Scherzinger their categories in last night's (September 23) Boot Camp episode, but it has been rumoured that he could soon join them to help bring viewers back to the struggling show.
"The UK figures have been slowly dipping since Simon and Cheryl Cole left," an insider told The Sun. "The new judges just don't have chemistry.
"Until this weekend, it was obvious Simon felt he'd outgrown the UK. But with disappointing figures in America, bosses feel he may come back to Britain where he's loved and missed."
It was claimed earlier this month that Scherzinger, who only joined The X Factor this series after leaving the US version, could be axed to make way for a new judge.
Cowell initially wanted Cole and Dannii Minogue to return to The X Factor this year alongside Barlow and Walsh, according to his biographer Tom Bower.
