There would be no public interest in lifting an injunction banning the media from naming a well-known celebrity who is alleged to have taken part in extramarital sex with two people, the supreme court has ruled.
In a brief hearing on Thursday morning, the court said the banning order should remain in place at least until there is a trial to settle the case.
In what will be an influential decision in cases involving privacy, the internet, and the media, judges voted with a 4-1 majority for the injunction to remain in place.
In January, the Sun on Sunday planned to run a story about one-half of the well-known celebrity couple – a person known only by the initials PJS – taking part in a "three-way sexual encounter".
The newspaper told the couple of its intention to publish and the couple's lawyers took out an injunction to stop it, on the grounds it would be a breach of privacy and harmful to their two young children.
News Group Newspapers, the Sun on Sunday's parent company, overturned the privacy injunction in the court of appeal in April, on the grounds that the story and the couple's identity had been widely published in the US and in Scotland, as well as on social media. But despite this, an interim injunction was granted.
And on Thursday the supreme court overruled the court of appeal and said the injunction should remain in place. Publishing any information that could identify the couple could result in contempt of court charges.
The court accepted that multiple magazines and websites in the US and Scotland have named the complainant and the name has been widely shared on social media. Various British newspapers have attacked the injunction as unfair and undemocratic.
Lord Mance, one of the five judges sitting in the case said: "Publication of the story would infringe the privacy rights of PJS, his partner and their two children.
"There is no public interest, however much it may be of interest to some members of the public, in publishing kiss-and-tell stories or criticisms of private sexual conduct, simply because the persons involved are well-known. And so there is no right to invade privacy by publishing them."
It would be different, he said, if the story was about someone in public office who had done something contrary to the public image they have cultivated, but this didn't apply to PJS.
On the widespread online publication of the identity, Mance said: "it is true that the story had been available on social media, but if the injunction were lifted there would be extensive coverage in the Sun on Sunday and, there is little doubt, by other newspapers, as well as unrestricted internet and social media coverage, all of which would constitute additional and enduring invasions of privacy of PJS, his partner and his children."
He added that publication would also prejudice any future trial, which is now expected to be held at the high court later this year. It was likely that a trial would grant a permanent injunction, the judge said.