A video of Britney Spears rehearsing for her upcoming Las Vegas residency has been uploaded online.

The singer is due to kick off a two-year stint at Planet Hollywood on December 27 as she performs both her hits and some new tracks.

E! are set to show a documentary of the US star's rehearsal efforts on December 22 entitled I Am Britney Jean.

A clip from the program has now been issued online, with a trim looking Spears seen running through some dance moves with choreographer Antony Ginandjar.

The singer says in the clip: "This year I have new choreographers and they're new, upcoming and fresh guys, so their stuff is really hard. It's more rewarding when you perform something that is really hard to do."

Spears' backing music is meanwhile her hit single 'Toxic'.