Heidi Range claims life within the Sugababes was completely ''unbearable'' until Keisha Buchanan left the group in September last year.
The Sugababes - who underwent their fourth line-up last year when founding member Keisha was ousted and replaced by star Jade Ewen - are on "equal footing" with their latest line-up, which also includes Amelle Berrabah, says singer Heidi.
She said: "Now we're all on an equal footing... before that, we never knew from one day to the next what mood or hurtful comments to expect. The last year was unbearable because it was so stressful. We'll go on and on. The Sugababes has never just been about one person."
Despite the latest line-up upheaval, the chart-topping band claim to be on top form once again.
Amelle vowed: "We are back with a vengeance, stronger than ever."
Jade was only given a few minutes to decide if she wanted to join the Sugababes and even though she was in the process of launching a solo career she knew she couldn't turn the opportunity down.
The 22-year-old beauty said: "I woke up to one of the Sugababes management team shouting through my letterbox... I realised that this wasn't an opportunity I could afford to miss. But I'd blown any chances of a solo career by taking off like that."