East, who was a runner up on The X Factor in 2014, was the subject of a joke by Cowell on Saturday 1 December, when he told his 2018 finalist Scarlett Lee that he "didn't want to see her in the jungle drinking worm juice".
"I want to see you on Broadway or the West End selling records," he continued. "You've got a big duet to come, Scarlett. This could change your life."
Viewers were quick to call out Cowell and point out that, given he was the one managing her career, he could take some of the blame for her perceived lack of success as a pop star.
On Sunday night's episode of I'm a Celebrity, East's trial involved hitting a pinata to release the stars. As she hit the final one, which was shaped like a wedge of cheese, Dec urged her to keep going and "picture Simon Cowell's face" as she whacked it.
East parted ways with Cowell's record label Syco in 2017, three years after becoming the first X Factor contestant to reach number one on the UK iTunes chart during the competition, with her cover of "Uptown Funk" by Mark Ronson ft Bruno Mars.
Her debut album Love, Sax and Flashbacks, was released in 2015 and made it to number 14 in the UK charts, with her lead single "Sax" making it to number three in the UK and going platinum.
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