His comments follow the controversy which blew up last month after the Countess represented the Rover car firm, a client of her public relations firm R-JH.

"As far as I can work out, she is doing extremely well at promoting Britain and Britain's businesses and Britain plc," the Earl told The Daily Telegraph.

Edward said that there was never any suggestion before their marriage that Sophie would leave her job.

He added: "My wife has not undertaken any public engagements in her own right at all. She's got her job to do, it's an extremely successful business and she should be allowed to get on with it.

'Jury out'

"It is not a conflict of interest in any way, shape or form. It was agreed all the way along that she would continue working.

"There was never any time when she wasn't going to be able to carry on doing the job."

The Earl also replied to accusations of trading on his own royal status in his work with Ardent Productions, the film production company he founded six years ago.

"There is always going to be the conflict between that section of society that thinks the wider members of the Royal Family should be able to earn their own living and the section of society saying it's not right for members of the Royal Family to be involved in business. The jury's out on that one."