"We're still working together closely on a few other things to do with the band, and I'm still holding a torch that she's going to join us on stage for one of our 13 shows — but that's just me," the singer confessed.
"Right, now it's not happening, but I figure if I say it enough — just like I did with the tour — then maybe it will happen.
"She gives us her blessing, but she was always quite clear that she wasn't really into reuniting or performing."
Brown also revealed that she's hoping the Spice Girls tour will extend Down Under.
"I've always been the one championing for the Spice Girls to reunite and get back together and do a world tour. We did want to come out with six tour dates in the hopes that our fans would be there for it, and the overwhelming support means we're doing 13 shows … but hopefully it keeps snowballing," she told the radio hosts.
In early November, Brown, Melanie "Mel C" Chisholm, Geri "Ginger Spice" Horner and Emma "Baby Spice" Bunton announced they'd be getting the band back together for a UK stadium together — but without Posh, who's reportedly too busy with her fashion label.