Spice Girl Melanie Chisholm has said she cannot envision the girl group reforming unless all five members are involved.
The musician, known as Mel C, said that and Victoria Beckham would not commit to a comeback with the pop group.
Speaking on ITV's The Nightly Show, she told Davina McCall: "That's where I'm at right now, that's where myself and Victoria are at.
"It's not really doing the band justice to go out as a four-piece, whoever is missing, it doesn't matter."
She added: "For me, Spice Girls, it's like a jigsaw puzzle.
"It's different to other bands because you look at Take That and they are going out as a three-piece, and they are brilliant, I love the boys.
"But with the Spice Girls everything about us was the individuality and what that created together."
The band last appeared on stage together at the 2012 Olympics closing ceremony in London.
Mel C appeared on Friday's The Nightly Show which saw McCall pass on the presenting baton to X Factor host Dermot O'Leary before next week's episodes.