Mel C has reportedly told her fellow Spice Girls she won't join the reunion unless the group take singing lessons.
Sporty Spice, real name Melanie Chisholm, is said to be joining Mel B, Emma Bunton and Geri Horner on a comeback tour, according to the Sun, following years of objections to the reunion.
The singer, 44, plans to oversee the musical arrangements when the group perform the string of hits from their back catalogue, which will include working with a live band.
But the Wannabe hitmaker reportedly wants the girls to take singing lessons to make the shows credible, as they haven't toured together in a decade.
However, the Lancashire-born beauty hasn't been able to convince Victoria, also known as Posh Spice, to rejoin the iconic girl group.
The tour is being put together by Modest Management, the brains behind One Direction, and the group's original manager Simon Fuller.
MailOnline has contacted representatives for Mel for comment.
Since splitting, the five women behind iconic songs such as Wannabe and Spice Up Your Life, have all gone on to successful business ventures.
Victoria Beckham has gone on to forge a career in fashion and launched a successful clothing line, while famously marrying David Beckham and having four children.
Meanwhile, Emma Bunton has ventured into presenting. She hosts the breakfast show on iHeart Radio and was recently announced as part of the team on the US version of the Great British Bake Off.
Melanie Brown, known as Mel B or Scary Spice, has become one of the best known faces on television and has been a judge on America's Got Talent since 2013.
Like Scary Spice, Ginger Spice, real name Geri Horner has become a judge, working on Australia's Got Talent, she's also written children's books and continued her music career.
Likewise, Sporty Spice has worked on the Asian version of the show and forged a successful solo career.
Mel B has been the most vocal about the reunion. Earlier this week she appeared on The Late Late Show With James Corden where she once again claimed the girl group will go on tour.
The America's Got Talent judge said on the US late-night talk show it's "100 percent happening". She went on to reveal to that three other band members are "for sure" joining her back on stage.
The band last performed together at the opening ceremonies of the London Olympics in 2012.
Since then 'Posh' Spice has repeatedly shot down reports that the popular group would be reuniting.
"I'm not going on tour," Victoria told Vogue earlier this year. "What does that look like in the future? It's not me in a catsuit."