The iconic pop group would love to reform to celebrate their 20th anniversary this year, with several major venues keen to host the comeback.
An insider told the Daily Star Sunday newspaper: "A Spice Girls reunion in Vegas could easily generation $100 million worth of PR in a few weeks and earn the group £25 million in the process.
"There's huge interest from various major casinos and hotels so it's just a case of whether the girls can persuade Victoria to change her mind on the project."
The fashion designer - nicknamed Posh Spice during her time in the 'Wannabe' group - is said to have given her former band mates permission to reform as a four piece, but the deal is only for a full reunion.
The source added: "Posh is more than happy for the four girls to do it without her but the problem is the offer is only on the table for all five of them."