Former Spice Girls Emma Bunton and Melanie Chisholm are set to reunite on stage for a Christmas special. The pop stars will perform the group's first-ever U.K. Christmas number one, 2 Become 1, at the London Regent Street Christmas Lights Switch-On event on Saturday (09Nov13). Chisholm says, "I'm so excited to be performing this year with my lovely friend. "We both absolutely love this time of year and have so many wonderful Christmas memories. This will be one to cherish."