But in a radio interview with 2Day FM's Grant, Ed and Ash this morning, Mel B admitted the tour isn't locked in.
"You know me by now," she said. "I always say the Spice Girls are going to continue and continue and tour the whole world.
"My thing is, and I've got a bee in my bonnet about it, is that we need to come to Australia first out the gate. I announced it on stage, yes, without everybody else signing off 100 per cent, but I figured if I put it out there maybe it's going to happen."
Ash London said, "So, you're manifesting it?"
"Exactly," Mel B replied.
The singer known as Scary Spice said her bandmates are "not on board fully, yet," with the idea of an Australian tour. "But I will make sure it actually does it happen," she added.
If the tour does go ahead, 2Day FM co-host Ed Kavalee suggested to Mel B that the Spice Girls could invite a few different Aussie singers to get up on stage with them each night to sing a few songs.
"We did think about that … when Victoria (Beckham) was not up for performing," she said.
But they decided against the idea, with Mel B explaining, "We just thought, you can't replace anybody in this group".
Mel B was also asked by the 2Day FM hosts about Geri Halliwell's emotional on stage apology at the group's final show at Wembley Arena on the weekend.
Geri apologised to her bandmates and the group's fans for quitting in 1998.
"It suddenly occurred to me this afternoon, I need to say something I should have said a long time ago: I'm sorry," she said. "I'm sorry I left. I was just being a brat. It is so good to be back with the girls that I love."
Speaking about it on air this morning, Mel B joked, "It's about time, bitch!"
"It actually made cry just a little bit inside. That was nice."