Simon Cowell will fill Britney Spears' 'x factor' dressing room with figs and prunes.

The TV mogul has signed the singer to appear as a judge on the US version of talent show - for a reported $15 million - and one of the promises he made to clinch The Deal was to keep supplying her with the fruits she usually insists on in her tour rider.

A source told the Daily Star newspaper: ''He promised to fill her dressing room with them. That'll make her 'regular' now.''

Meanwhile the 'Toxic' singer is said to be embarking on a six-week course of intensive training to prepare her for the show.

Britney has promised to be ''glammed up'' and totally dedicated to the programme, which is expected to return to TV in the autumn.

A source said: ''Britney has to look picture perfect, even during downtime. Simon has laid down the law - he's paying for 'superstar Britney' not the 'trailer trash' version she's occasionally become known as.

''Her people have promised she will be transformed. She'll be glammed up, slimmed down and totally focused on the show

''Her diet includes lots of protein and superfoods to helps speed up her metabolism. The plan is to keep her full in between meals with vitamin juices, so she doesn't get hungry and grab junk food.''

Insiders estimate the makeover could cost over £250,000 and she will be working very closely with a team of stylists on every detail of her look.

The source added to Closer magazine: ''A full-time stylist will plan every detail of every outfit. She'll spend around four hours in The Hair salon and have regular manicures and pedicures.''