Prince William's girlfriend has cancelled plans to stage an exhibition of her photography work because she can't cope with the pressure.

She is working full-time as a website photographer for her family's online and catalogue party business, Party Pieces, and she's just not got around to it

Kate Middleton - who has been secretly preparing a portfolio of pictures for months - has told friends she will indefinitely postpone the planned showing of her work.

A friend of 28-year-old Kate said: "It's very much still an aspiration of hers but it's been put on the back burner. If it ever happens, it may be long after the autumn. She is working full-time as a website photographer for her family's online and catalogue party business, Party Pieces, and she's just not got around to it."

Princess Diana's former detective, Ken Wharfe, said royals were trying to prevent Kate from becoming another Diana.

He added to the Daily Express newspaper: "They want young women who come into the family as commoners to have their babies and be quiet and supportive of their husbands. What they don't want is anyone stealing the attention away from the Royal Family. They don't want another Diana up there. I can well imagine William saying, 'This exhibition is a nice idea, Kate, but is it really going to work'?"

Kate - who studied photography as part of her history of art degree at St Andrews University, where she met the prince - had planned the autumn exhibition to raise money for charity.