The ruling by Mr Justice Lindsay that Hello! had breached a confidence could be used against the media in future cases, media lawyers said today.
But it would not have the devastating results of a full law of privacy which would effectively end the exploits of the paparazzi and severely curtail investigative journalism.
Christopher Hutchings, of Charles Russell, who defended Hello!, said newspapers which put out a story designed to “spoil” an exclusive by a rival could well fall foul of the confidence law as it now stands after this judgment.
He said the idea that an exclusive contract represents a trade secret is a radical extension of the law.
It could be applied not just to contracts between celebrities and newspapers but also to anyone who has sold their story.
“It will have far more wide-ranging effects on the media than just celebrity weddings,” said Mr Hutchings.
Lawyers will seek to expand this law in future claims unless it is successfully challenged at the Court of Appeal.
He said if the judge had found there had been an invasion of privacy it could have stopped the media taking pictures in any public place and would have been a “catastrophe”.
Although today’s ruling will have far less impact than a privacy law, the media will still have to question how photographs were taken and how reporters came to be in possession of notes taken at any private meeting.