Much of the harm that the courts had tried to prevent in January by barring the publication of details of a celebrity couple’s sex life has already occurred, Court of Appeal judges ruled today.

In a widely awaited judgment in PJS v News Group, Lord Justice Jackson said that the injunction preventing identification of the parties involved ‘must be set aside’. Courts 'should not make orders which are ineffective', he concluded, adding: 'It is in my view inappropriate (some may use a stronger term) for the court to ban people from saying that which is common knowledge.'

However the details at issue will remain confidential for two days while the celebrity’s lawyers, media firm Carter-Ruck Solicitors, mount a challenge at the Supreme Court.

Jackson also dismissed a line of argument that the public debate stirred up by 'defiance' was in itself grounds for lifting the injunction. 'It cannot be permissible for the media to stir up a debate about an injunction to which they are subject and then rely upon that debate as a ground for setting aside the injunction.’

Jackson said that the injunction, granted on 22 January restraining publication by the News Group Newspapers, publisher of the Sun on Sunday, on the grounds of misuse of private information and a breach of confidence, had held for 11 weeks. 'Then things changed,’ he said.

On 6 April 'a widely read magazine in the US’ published an account naming those involved; other publications in the US, Canada and Scotland followed suit. 

On a claim that the media had acted ‘defiantly’, he said: 'The difficulty with this argument is that the internet and social networking have a life of their own. Furthermore, this court has little control over what foreign newspapers and magazines may publish.’

As a result, 'much of the harm which the injunction was intended to prevent has already occurred’, he said.

'The "wall-to-wall excoriation” which the claimant fears has been taking place for the last two weeks in the English press. There have been numerous headlines such as “celebrity love cheat” and “Gag celeb couple alleged to have had a threesome”. Many readers know to whom that refers.’

While he said no quantitative evidence is available about how many people were aware of the celebrity’s identity 'it does appear that those who want to find out the individuals’ identities have already done so’.

Jackson said that what the newspaper proposes to publish is likely to be a breach of the right to private and family life. 'Once the injunction has been lifted, it will be a matter for NGN to decide whether they wish to go ahead with publishing their story. 

'If they do so, that will not be a contempt of court, but they will still face the claimant’s claims for breach of confidence and misuse of private information.’

Lady Justice King and Lord Justice Simon agreed with the judgment.