The new video sees the trio hanging out on Venice Beach in Los Angeles before heading to the desert with a marching band.

Reinvented girlband Mutya Keisha Siobhan have unveiled the music video for their comeback single Flatline.

The trio, who are the founding members of the Sugababes, unveiled the visual for the retro track, which will go on sale later this month, on YouTube.

In the four-minute promo, shot by renowned fashion photographer Auleta, the girls can be seen hanging out on Venice Beach in Los Angeles before heading into the desert with a marching band.

"So chic!!! The girls are having fun in this video! I love them!" one fan said.

It is Keisha Buchanan, Mutya Buena and Siobhan Donaghy's first video together since they filmed Soul Sound as the Sugababes in 2000. It is also the first official release since the girls, who have all left the Sugababes' ever-changing line-up, reunited last summer.

Since reforming they have been working with Emeli Sandé, producer MNEK, Sia and Sugababes producer Cameron McVey on their new album.

They recently made a triumphant return to the stage at London's Scala nightclub.

"We just wanted to go back on stage and keep going," they said. "We're really pleased with how it went.

"Obviously a lot of the set was new songs and you never know how they're going to go down, but they got a great response. It was over too quickly! We didn't want it to end."

Flatline is scheduled for release on 15 September. The new album will hit stores early next year