Pop star Geri Halliwell has opened up about her disappointment at the forthcoming end of the Spice Girls musical, 'Viva Forever!'.

The production only launched back in December last year, but ticket sales haven't been as promising as initially hoped so the show will come to a close on June 29 with one final performance.

Writing on her official blog today (May 22), the 'Wannabe' hitmaker explained that she doesn't understand why the musical wasn't as popular as predicted because she thinks it is fantastic: "Over 4 years ago it started with a conversation in a Kitchen; Laughing… Joking… full of promise, dreams & optimism."

"We managed to get one of the most successful Theatre producers to do our show! A great writer, our Spice music… I felt confident - almost cocky it was going to be a huge success."

Questioning the production, she continued: "What went wrong? Was I biased? Blinded because it was a show with our music? Was it the lighting? The set? The choreography? The press? The story? It had a bumpy start but the cast and director worked really hard, made great changes, and I can hand on heart tell it's not s**t! - It’s good entertainment!"

Halliwell added that she is now heading down under to be a judge on 'Australia's Got Talent' and thanked everyone who participated in 'Viva Forever!' for such an amazing experience: "I don’t regret it. I got to meet and work with the fabulous Judy Craymer, the producer whom I hope to be a friend for life."

"So this is to say thank you to all the people who tried for the Spice Girls, who had the guts to put their heart and soul into Viva. Even if something doesn't work, I admire anyone who tries, because a lot of people are afraid to. Thanks to all the cast of Viva, the musicians, Judy, Jennifer, the Spices and to all the fans and theatre-goers who came."

Watch a trailer for 'Viva Forever!' below: