The Sugababes - Heidi Range, Amelle Berrabah and Jade Ewen - and their record company have started legal proceedings against former band member Mutya Buena over the use of the band name.
The pop trio - Heidi Range, Amelle Berrabah and Jade Ewen - and their label Island Records have filed a notice of opposition against group founder Mutya's application to gain the rights to the name, which was logged in March with the European Trademarks Authority.
In a letter to the agency, Island Records stated that because of the "similarity of the goods and services" provided by the Mutya "there is a likelihood of confusion on the part of the public".
All parties will now have to wait until a decision has been reached.
If Mutya's application is ultimately successful she would have the rights to use the Sugababes band name to sell a variety of products, including CDs, DVDs, T-shirts and books.
Heidi replaced Siobhan in 2001, while Keisha left in September 2009 and Jade took her place.
Heidi previously claimed she and the current line-up would have no problem keeping the name because their record company owns the rights.
She said: "Our record company owns the name so there are no conversations about who owns the name. I signed with Mutya and Keisha years ago, so we've still got the name."