In February 1997, the group opened the BRIT Awards with "Who Do You Think You Are". The Union Jack dress that Geri Halliwell wore during the performance made the front page of various newspapers, and is now remembered as one of the most iconic symbols of Cool Britannia. "Who Do You Think You Are" became the official single of the 1997 Comic Relief, a video with the Sugar Lumps—a satirical version of the group—was released to help raise money for charitable causes and donated all the proceedings from the single.
"Who Do You Think You Are" was a commercial and critical success, with Melanie Chisholm's vocals receiving praise from pop music critics. Released with "Mama" as a double A-side single in March 1997, it became the group's fourth consecutive number-one single in the United Kingdom, making them the first act in UK chart history to have its first four singles reach number one.