First look at Britney in Glee

Gleeks contain yourselves! Britney Spears has given a sneak preview of her cameo on US series Glee.

The star posted an image from her first day's shoot on her Twitter page. Standing alongside her assistant, the star, 28, can be seen dressed in a waistcoat and wearing glasses.

She told fans: "Having so much fun on set!! Can't wait for you guys to see the episode! -Britney."

Glee creator Ryan Murphy said earlier this year that the episode dedicated to the pop princess would be called Britney / Brittany and will poke fun at choir leader Mr Schuester, who does not want the Glee club to cover the hit singer's songs.

The episode is sure to be one of the highlights of series two, which returns to US screens in September.