Britney's dress-down day

Skin-tight costumes are her pop star trademark.

But when Britney Spears is out of the spotlight, she likes to give herself a little more room to move.

On a break in Los Angeles, the 22-year-old singer wore a relaxed outfit of frayed shorts and a loose shirt.

Her hair was piled haphazardly on her head and with sunglasses and flipflops, she looked like she had slipped into something far more comfortable than her average stage costume.

'To put it bluntly, Britney looked a bit of a mess,' an onlooker said. 'She was dressed in clothes that didn't match and her shirt was only buttoned up halfway, making her look even more casual.

'She was just slouching about. To top it all off, she was smoking as well - which can't be good for her young fans to see.'

Miss Spears is due to arrive in London over the weekend to start the European leg of her latest tour.

Her choice of revealing outfits for the show has already raised eyebrows in the U.S., along with her risquè dance routines. She is said to be concentrating on her career after a tumultuous time in her private life, including a 55-hour marriage to a childhood friend.