Simon Cowell and Dermot O'Leary have fallen ill ahead of the first 'X Factor' audition on Friday (10.06.16).

Simon Cowell

Simon Cowell

Sources say it is "touch and go" as to whether the music mogul, 56, and comeback presenter, 43, will make it to Leicester City's King Power stadium to kick off this series of the talent show, after Simon pulled out of a charity ball last week and Dermot was forced to skip the Glamour Women of the Year Awards on Tuesday (07.06.16).

A source told The Sun newspaper: "Dermot is a regular guest at the Glamour Awards so his absence proved how ill he is.

"He was supposed to be at the auditions but it's touch and go whether he will be well enough."

Dermot is returning to host 'The X Factor' after he was replaced by Olly Murs and Caroline Flack in last year's series following his eight-year run.

And he admitted he'll need all his strength to keep up with the panel, which features Sharon Osbourne, Louis Walsh, Nicole Scherzinger and Simon.

Following the announcement, Dermot wrote on Twitter: "Well ... That'll keep me on my toes (sic)."

Meanwhile, Simon claimed recently he is a more relaxed judge since his two-year-old son Eric - who he has with girlfriend Lauren Silverman - was born.

The talent manager - who was known for his tough stance on the show from the very beginning - said: "Lauren is great. And there's no question when you actually have a kid, it does make you feel different because you understand how you would feel if it was your son up there.