The singer, 46, rose to fame on the 2001 ITV talent show alongside Tony Lundon, Kevin Simm, Jessica Taylor and Kelli Young.
All five reached the final but missed out on places in the winning group Hear’Say - a twist that led to the creation of Liberty X, who went on to score 10 consecutive UK Top 20 singles before splitting in 2007.
Since 2017, the group’s three female members have continued performing as Liberty X.
Speaking on Paul Brunson’s We Need To Talk podcast, Michelle suggested the rivalry was intentional.
She said: “There was a war from the get-go.
"We were constantly pitted against each other in a world we were trying to navigate.”
She claimed the hostility didn’t just come from Hear’Say themselves, but from the team surrounding them
She said: “It was evident they wanted us to fail. Not just Hear’Say as a team, but the people around them.
“And so that would have then stirred up the pot with the Hear’Say members in order to add fuel to the fire when they did interviews about how they were bigger and better and we were not so… and that we were running on their coattails.”
Michelle said the tone of the rivalry felt especially harsh because the two groups had bonded during the audition process.
She explained: “It felt really harsh. We didn’t know how to navigate it. It felt like it wasn’t the five people that we met in the audition process."
Despite the tension, she admitted she wanted to stay close with Hear’Say’s Suzanne Shaw, whom she had connected with during filming.
She continued: “And alongside all of this, all I kind of wanted to do was reach out to Suzanne because that’s like one of the people that I got really close to … and be like, ‘how is it? What’s it like?’
