Keisha Buchanan had "a really hard time" in her early days of Sugababes.

Keisha Buchanan shot to fame as an original member of the Sugababes

Keisha Buchanan shot to fame as an original member of the Sugababes

The 39-year-old singer was a founding member of the girl group alongside Mutya Buena and Siobhán Donaghy but "wasn't really close" to Siobhan in those days and had to endure a negative atmosphere until she left and was replaced by Heidi Range.

Speaking on the 'Receipts' podcast, she said: "From the age of 12 to maybe 16, that's when the first shakeup came. 16 going on 17. It was a really hard time because I think we...Siobhan and I weren't really close when we were younger, it was such a shakeup. It was kind of...it just wasn't a nice atmosphere. So after she left, quite quickly, Heidi came in. We were told that there was an auditioning process happening so we auditioned a friend and then Heidi came along.

"Our friend was a year and a half younger than us and in the UK, you can't work more than a certain amount of time. And we were just turning 17 so we could do more, collectively, management said it was better to have Heidi. It just made sense for her age, she was 18."

The 'Push the Button' hitmakers went through a number of lineup changes in their heyday that also involved Amelle Berrabah and Jade Ewen at various times and while they are now back to the original trio, Keisha noted that during that initial "shakeup" period, it was as tricky for the girls as a band as it was for the fans.

She said: "You don't have months and months of someone saying that they want to leave, so while the fans are going through it, we're also trying to figure out what's next but when we came back, we came back with a number one 'Freak Like Me'. From there, it just went commercially massive."