Geri Halliwell decided to quit the Spice Girls after her bandmates refused to allow her to do a solo interview with a British breast cancer charity.
During her Spice Girl heyday, the singer revealed how she had found a lump in her breast and feared she could have had cancer.
U.K. charity Breast Cancer Care approached Halliwell in 1998 to help publicise the cause by giving an interview on her cancer scare.
But the star reveals that her fellow Spice Girls did not want her conducting interviews alone - and it was then that Halliwell decided to walk away from the group at the height of its fame.
In an interview on Britain's Piers Morgan's Life Stories, says says, "I was asked to do an interview for Breast Cancer Care and they asked me because I had a scare a long time ago and I was like, 'fantastic'.
"Sometimes I just wanted to show up as just myself and for some reason it got stopped. They (the band) said, 'We all want to do it or you’re not doing it.'
"I was like, 'Do you know what? I haven’t come this far in the game to be told not to do that.' So that was the defining moment.
"We were on this tiny private jet flying into London and I was just went, 'Bye girls,' And I thought, 'Maybe you’re going to be happier without me.' I didn’t say I was leaving but the next day I said, 'I’m not coming back.'"
The band reunited in 2007 for a world tour before parting ways again in early 2008.