By Jon Silverman Legal Analyst

Kate Middleton at Prince William's Sandhurst passing-out parade

At a time when media interest in the future of royal escort, Kate Middleton, has never been keener, the decision by News International not to use paparazzi photos of her looks perverse.

But a closer examination suggests that the action has been driven by the fast-developing law on privacy rather than journalistic altruism.

It is reported that lawyers had already been instructed to obtain an injunction against the photographers who dog Ms Middleton's every step unless they desisted.

Test cases

And case law established by the European Court of Human Rights suggests that a judge would probably have granted the relief she sought.

If you are going about your daily life, whether at work or buying a pint of milk, you are entitled to some privacy Sarah Webb, defamation lawyer Ex-aide condemns paparazzi Send us your comments

The pivotal case was brought by Princess Caroline von Hannover against the German paparazzi who had pestered her for years as she went about her daily life.

The Strasbourg court ruled unanimously in June 2004 that her right to privacy had been breached.

The court held that even well-known individuals had a legitimate expectation that their private life would be respected - whether in a secluded or a public place. Moreover, the state had a positive obligation to ensure that this expectation was met.

Public interest

A leading UK Appeal Court judge, Lord Justice Sedley, has said this means that the courts must protect against privacy where it is not justified by the "free speech requirements of genuine public debate".

Elton John failed in a legal bid to stop paparazzi photographers

Recent judgments in the English courts have tended to side with those seeking injunctions against media intrusion - with the exception of a failed attempt by Elton John to prevent photographers snapping him leaving his home.

Sarah Webb, head of defamation at Russell, Jones and Walker, says: "The courts are drawing the line at constant, repeated media harassment.

"They are saying that if you are going about your daily life, whether at work or buying a pint of milk, you are entitled to some privacy. So I think News International was merely being pragmatic by making this announcement as well as earning some brownie points with the public."

Towards the end of 2006, the Prince of Wales won a legal victory against the Mail on Sunday over unauthorised publication of extracts from his private diaries.