Two recent cases, Tattersall v Tattersall [2025] EWHC 2558 (KB) and Blake v Fox [2025] EWCA Civ 1321, show how courts are drawing the line when it comes to proving serious harm in defamation claims.
Legal framework
Section 1(1) of the Defamation Act 2013 provides that a statement is not defamatory unless its publication has caused or is likely to cause serious harm to the reputation of the claimant.
Tattersall v Tattersall
Facts
The High Court struck out a libel claim arising from a single Facebook post shared during a family dispute involving a mother in law (claimant) and daughter in law (defendant). The post, seen by about fifty people, accused the claimant of trying to make the defendant homeless and lying about her. Whilst the words were held to be defamatory, the claim was struck out because the claimant could not show that the publication caused, or was likely to cause, serious harm to her reputation.
Court's reasoning
The court emphasised that the serious harm test requires objective evidence of reputational damage. The claimant’s personal distress was not relevant to the question of harm to her reputation. The court also held that there was no real prospect of the claimant establishing an inference of serious harm based on the Facebook post, due to its limited publication, the modest gravity of the allegations and the lack of evidence from those who had read the post that it had caused her reputational harm.
The court emphasised that the serious harm test was intended to prevent trivial claims and struck out the claim, finding that it disclosed no reasonable grounds and had no real prospect of success.
Blake v Fox
Facts
The Court of Appeal revisited a high-profile X (formerly Twitter) spat in which Mr Fox accused the claimants of being "paedophiles" after they had labelled him "[a] racist". At first instance, Mr Fox’s counterclaim failed for lack of serious harm, the claimants succeeded and were awarded £90,000 each in damages.
The Court of Appeal held that there was compelling support for an inference that the mass publication of each of the claimants' "racist" tweets seriously harmed Mr Fox's reputation and that this was the only conclusion reasonably available to the judge. Mr Fox's counterclaim was remitted for retrial on his defences of honest opinion and truth.
The Court of Appeal also reduced the claimants' damages to £45,000 each, citing mitigating factors such as Mr Fox’s deletion of the tweets and clarifications given in interviews, as well as proportionality.
Court's reasoning
The Court of Appeal also affirmed the law in cases where the defendant is seeking to argue that the claimant already had a bad reputation, as the claimants had sought to do in the counterclaim. The Court reaffirmed the continuing relevance of the rule in Dingle v Associated Newspapers Ltd [1964] AC 371 (HL) when assessing serious harm. Under this rule, the defendant can’t rely on publications of the same/similar statements by third parties to show that the claimant already has a bad reputation and must instead call witnesses who know the claimant and "have had dealings with him" to give evidence about this.
The court also held that, when assessing whether there had been general harm to the claimant's reputation, it is not permissible to rely on acts of the claimant to show that he already had a bad reputation at the time the alleged libel was published.
Comment
These two cases highlight the practical realities of the serious harm test under the Defamation Act 2013.
Tattersall demonstrates that limited publication and modest allegations will rarely satisfy the statutory threshold without clear evidence of reputational impact. Claimants must go beyond asserting hurt feelings and show objective harm supported by facts.
Conversely, Blake illustrates that scale and context matter: mass dissemination of inherently damaging allegations can justify an inference of serious harm, even without direct evidence from readers. The Court of Appeal’s reaffirmation of the Dingle rule underscores that defendants must produce credible witness testimony instead of relying on third-party publications or unrelated acts to establish a claimant's pre-existing bad reputation.
