St Trinian's Liverpool Street station dance

It's not a sight day trippers would expect to see as they arrive for a Sunday out in London.

Are you sure it's Aloud? passengers at Liverpool Street station yesterday may have ended up as extras in the St Trinian's film

Hundreds of uniform-clad schoolgirls danced and sang their way across Liverpool Street station yesterday, led on by a mischievous-looking pop star.

Girls Aloud's Sarah Harding grinned for the cameras as she and her fellow cast members strutted their stuff across the concourse for the new St Trinian's film.

Wearing leather hotpants, a low-cut white blouse and a school tie slung casually around her neck, Harding, 27, led the girls in a routine reminiscent of a recent TV advert for T-Mobile, which saw hundreds of people break into an impromptu dance routine at the station.

Rising star: Sarah on station escalator

Harding and actresses Tamsin Egerton and Talulah Riley were shooting a scene for St Trinian's II: The Legend of Fritton's Gold, in which Harding appears as a pupil called Roxy.