Sugababes star Keisha Buchanan's early years as a pop star were "gruelling"

She explained: "The industry is completely different to when we first started and it was gruelling.

"It's like half the amount of work we used to do in terms of promo and things like that and even just prep - rehearsals were way longer because we were trying to get the sound right and we would have on stage speakers hearing ourselves, and now we're all collectively wearing In-Ears [monitors that allow singers to hear]."

Siobhan, 38, admitted the band now have much more creative control over their music than ever before.

She told Sky News: "We know what we're expecting, we've got an amazing new band and we have all the creative input we want, and I think that, you know, it's just the dream really."

There have been numerous iterations of the band over the last 20 years, and Mutya has confessed to learning a lot about herself and the music industry in that time.

The 37-year-old singer - who left the group in 2005 and later released a solo album, titled 'Real Girl' - said: "I think naturally you would do things differently, but I think the good thing about it is that we've learnt from lots of mistakes and a lot of things that we've gone through in the past.

"And now it's like just going out, having fun and just bouncing off each other."