Mr Justice Warby rejected arguments that 'cumulative harm' claims can satisfy the 'serious harm' test that applies under the Defamation Act 2013.
Media law expert Alex Keenlyside of Pinsent Masons, the law firm behind Out-Law.com, said: "This is the first time the courts have ruled on this specific point. While the decision is not really surprising, it provides helpful clarity on what is an important, if slightly esoteric, issue in the post-serious harm world."
Under the Defamation Act 2013, people must demonstrate that the publication of a statement has caused or is likely to cause serious harm to their reputation to bring a claim for defamation against the publisher.
When considering defamation claims, courts determine the defamatory meaning of statements and whether any harm caused or likely to be caused is serious enough to satisfy the 'serious harm' requirements.
The High Court has now ruled that a statement must be individually shown to meet the 'serious harm' threshold and that it is not permitted under the Act to aggregate a number of less harmful imputations in order to meet that threshold.
Mr Justice Warby said: "No authority has been cited to show that it was ever the law that a claim in defamation could succeed although none of the individual imputations conveyed by the publication complained of crossed the common law threshold of seriousness. If that ever was the law, I do not consider it can or should be held to be the law today."
"In my judgment, in the modern law of defamation, a statement is only defamatory of a person if, and to the extent that, it conveys an imputation about the person which tends to lower him or her in the opinion of right thinking people generally, and causes or is likely to cause harm to their reputation which is serious. The serious harm requirement cannot be satisfied by aggregating the injury to reputation caused by two or more less harmful imputations," he said.
The judge was ruling on the question of whether 'cumulative harm' claims can be brought under the Defamation Act 2013 in a broader dispute between a couple and two newspaper publishers.
Arnold and Jeanne Sube sued News Group Newspapers and Express Newspapersover 22 articles published online and/or in print in the Sun, the Express and the Daily Star within a two month period in the autumn of 2016. One aspect of their claim related to alleged defamation by the publishers, which the publishers have disputed.
In an earlier ruling in May, Mr Justice Warby determined that none of the comments made about the Subes in the articles, when considered individually, were "sufficiently harmful" to either of their reputations to satisfy the serious harm requirement under the Act. However, at the time he suggested that he would consider arguments over whether imputations conveyed in a statement that have a tendency to harm reputation should be considered collectively, rather than individually, for the purposes of the 'serious harm' test.
Subsequently the Subes raised arguments that such 'cumulative harm' applied in this case.
In his most recent ruling in the case, however, Mr Justice Warby said that, in general, a published article must be considered individually "for the purposes of assessing defamatory impact".
He said: "It will not normally be appropriate or even possible to treat a number of articles as a single 'statement' for the purpose of [the serious harm test], any more than it was at common law. It may, depending on the circumstances, be appropriate to take account of one or more previous articles as part of the context in which a given statement was published. But it is hard to see how the defamatory impact of one publication could be affected by the defamatory impact of a separate, later publication."
The judge said that statements complained of that appeared in one publication must be distinguished from those that appear in another, and further determined that it would be wrong for courts to have to "take account of meanings that are not defamatory" when considering whether a statement satisfies the 'serious harm' test. He also said that claims of defamation relating to more than one individual must be considered in isolation.
What constitutes 'serious harm' has been considered in a number of cases that have come before the High Court and Court of Appeal in London since the Defamation Act 2013 came into force. The Supreme Court is set to rule on the issue too after it granted some publishers permission to appeal a 2017 ruling of the Court of Appeal earlier this year.