Geri Horner has admitted it was "immature" to quit the Spice Girls in 1998.

She admitted: "There was a moment I decided to leave the band. I felt like it grown into this huge monster, bigger than the individuals, bigger than the band itself.

"Obviously there was bit of a ruction in the band and I was like,

'I just don't want to do this anymore.

"It was like, 'You're getting on my nerves and I don't know how to talk this through, so I'm out of here.' It was quite immature, looking back."

However, one good thing to come out of all the angst Geri had built up was that she put all of the negative energy into her first solo record, 1999's 'Schizophonic', as a "f**k you" to the world.

Speaking on 'Oprah: Where Are They Now?', she shared: "I used all that sort an 'F-you' and all that creativity, a bit of hurt and poured it into a solo album."

Geri also admitted that she felt Mel B "completely carried" the Spice Girls during their Olympics performance in 2012.

The quintet reunited for a one-off performance at the closing ceremony in London and Geri was most impressed by Mel B.

She said: "Mel B is an absolute performer. She's amazing! When we did the Olympics, she completely carried that. She would add something that was so bizarre and brilliant."

Geri has been working with Mel B and Emma on new Spice Girls music and a new track, 'Song For Her', their first material for nine years, was leaked last month.

A source said at the time: "Obviously the girls have been recording in the studio over the past few months.

"The plan is very much for there to be new music."

Geri, Emma and Mel B are expected to perform a one-off show in London's Hyde Park next July to celebrate the band's 20th anniversary but Mel C and Victoria have opted out.