Mutya Keisha Siobhan have premiered their new single's lyric video online.

The female trio, who feature original Sugababes members Mutya Buena, Keisha Buchanan and Siobhan Donaghy, are releasing the track 'Flatline' as their debut single.

Its audio has already been issued online but the single's accompanying lyric video has now also been unleashed ahead of the song's official release on September 1.

The group meanwhile are currently in the US to film the full video for 'Flatline', with the ladies pictured on a sunny beach.

As previously reported, MKS's debut album looks set for an early 2014 release, with the record unlikely to hit shelves in the US initially.