Stella McCartney couldn't buy advertising like this - an international superstar walking around with a giant shopping bag bearing McCartney's name.

Beyonce went on an almighty shopping spree in London, but her trip to Stella's store was clearly the most productive, judging by the size of her bag.

Shopping spree: The pair enjoyed shopping in London's designer stores

She hit designer stores including Selfridges in Oxford Street with her younger sister Solange, and looked stunning in her Swinging Sixties-style dress.

Mind you, she deserves a bit of a break from her gruelling tour schedule.

The UK leg of her Beyonce Experience tour saw her perform Wembley for the second night running last night, and she's off to Cardiff tonight before playing Nottingham and Manchester. Then it's one just night off before two more dates in Dublin.

Maybe she's buying some clothes to add to her stage wardrobe. After all, with such a tough schedule, there must be a bit of wear and tear on the outfits.

The singer is rumoured to have recently got engaged to her millionaire rapper boyfriend Jay-Z.

Jay-Z, real name Shawn Carter, is said to have popped the question while the couple were on holiday in the south of France, and is reported to have promised the bootylicious babe "the biggest diamond ring she can fit on her finger".

On the subject of marriage and children Beyonce said: "I want to get married and really want a family - in a perfect world I'd have two boys and a girl."

And on lover Jay-Z she added: "You know someone loves you by the way he treats you and respects you. Me and Jay respect each other."

The couple are said to planning to wed in Hawaii in the autumn.