In what is believed to be the first case of its kind, Mr Justice Eady granted a temporary injunction to the adulterer — who is in the “public eye” but can be identified only as CC — against the husband, AB.

The judge ruled that even a public figure engaging in an adulterous affair had a “right to privacy” under the European Convention on Human Rights to protect his wife and children. The order, which stands until further order or the main trial on February 12, gags the husband from spilling the beans about the affair from “revenge” or “spite” or to make money from the story.

As well as going to the press, AB had also threatened to disclose CC’s identity on the internet and instigate divorce proceedings in which CC would be named as co-respondent.

Lawyers said that the ruling could spell the end of “kiss and tell” disclosures in the media. The public figure, CC, had sought the injunction after AB discovered the affair.

After the private hearing, the judge gave his decision in open court. He said that the claimant had “conducted an adulterous relationship for some months with the defendant’s wife and now seeks the court’s assistance in preventing him from telling anybody about it”.

The couple had carried on their affair in hotels in England and abroad. “They were not recognised although it could be said they took the chance of being spotted,” the judge added.

The judge, who could find no legal precedent from the 19th or 20th centuries, said that he was faced with “the striking proposition that a spouse whose partner has committed adultery owes a duty of confidence to the third party adulterer to keep quiet about it”.

CC argued that he was seeking to reconstruct his family life and was concerned for his own wife and young children. His claim, which is disputed, is that at the time of the affair he did not know that the woman, who did not wear a wedding ring and made no mention of a current partner, was married.

His lawyer, Mark Warby, QC, said that even if CC was to blame for the problems of his wife and children, there was no reason why they should suffer more than was necessary and, in particular, through press intrusion. He said that the court should have regard to their rights under the European Convention on Human Rights, even though they were not parties to the dispute.

In the High Court in London, the judge said that CC’s wife was suffering stress and anxiety that required medical attention. There was also evidence of self-harm and of threats to commit suicide. It was that factor in particular that had led editors so far to hold back from publication and meant that AB — who fought the case on legal aid — had been frustrated in his efforts to exploit the situation for gain.

“He himself [AB] has not been deterred by this at all,” the judge said in his ruling. “He says it is just ‘bullshit’ and portrays himself as the victim.

“His attitude is that he is entitled to his revenge on the claimant and, if possible, also to some financial gain; if his own wife, or the claimant’s wife or his children, suffer incidental fallout, then that is the claimant’s fault.”

The judge added that, in an e-mail to the claimant, the defendant threatened to tell “every f*****g person in the world” by publishing the details on the internet. He said that, in a tape-recorded, and apparently drunken telephone call, the defendant told the claimant: “Listen mate, you’re going to be f****d when this goes to court.”

He added that since English law did not offer an enforceable right to privacy, CC’s claim was that publication would be a breach of confidence.

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