These may be related to the fact Keisha Buchanan, the only original Sugababe still in the lineup, quit the act a month ago, claiming she’d been pushed out.

“Following the recent and well documented change of line-up to Sugababes, there are a number of legal issues to be finalised by all parties in order that the band can move forward,” read a note on the act’s Web site.

“Sadly, whilst these negotiations are approaching completion, it will not be possible for the band to finalise its business affairs prior to Thursday’s event.”

The plot so far is that former bandmates Heidi Range and Amelle Berrabah denied they’d got rid of 24-year-old Buchanan, who has since been replaced by Jade Ewen – the U.K.’s Eurovision Song Contest entrant this year.

Range, Berrabah and Ewen were due to debut at the Scottish Royal Variety Performance at Glasgow’s Royal Concert Hall Oct. 8.

Band manager Mark Hargreaves is said to be confident that within a week it will be “business as usual for Sugababes” and there will be no need to cancel further engagements.

The Scottish Royal Variety Performance was being held in honour of The Royal Blind Society. Sugababes are said to be planning their own event and donating the proceeds to the same charity.

Click here for the Sugababes Web site.