The Supreme Court has held that the requirement to show "serious harm" under section 1(1) of the Defamation Act 2013 (the “2013 Act“) not only raises the threshold of harm which must be proved but also requires its application to be determined by reference to actual facts regarding the impact of the statement and not just to the meaning of the words: Lachaux v Independent Print Limited & Anor [2019] UKSC 27.

The primary purpose of the 2013 Act was to modify some of the common law rules which were seen unduly to favour the protection of reputation at the expense of freedom of expression. In particular, there had been criticism of the law allowing persons resident outside the UK with only very limited reputation within the UK being able to sue for defamation and obtain substantial damages. One of the new principal provisions of the Act 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". This so-called "serious harm" requirement has been the subject of much interest and uncertainty, and the present appeal was the first opportunity presented to the Supreme Court to consider it.


The claimant brought libel proceedings against the defendant news publishers following allegations which arose from the breakdown of Mr and Mrs Lachaux’s marriage, resulting in hostile divorce and custody proceedings. The couple resided in the UAE, where Mr Lachaux was granted custody of the couple’s only son. Following which, a number of British newspapers published articles making allegations about Mr Lachaux’s conduct towards his ex-wife during their marriage and in the course of these proceedings. The publications contained, among other things, allegations of domestic abuse and child abduction.

On a trial of preliminary issues, the High Court (Warby J) held that the effect of section 1(1) of the 2013 Act was to establish a new and more stringent statutory test requiring a claimant to prove, on a balance of probabilities, that a statement has caused or will probably cause serious harm. In assessing "serious harm", Warby J held that the court should have regard to all the relevant circumstances, including evidence of what actually happened following publication. This is in addition to considering the defamatory meaning of the words used, and the harmful tendency of that meaning.

Applying this to the facts, Warby J found that the harm caused by the publications complained of did constitute “serious harm” on the facts. This finding was based on: the scale of the publications; the fact that the statements complained of had come to the attention of at least one identifiable person in the UK who knew Mr Lachaux; that they were likely to have come to the attention of others who knew him or would come to know him; and the gravity of the statements themselves.

The Court of Appeal (Davis LJ giving the lead judgment) unanimously upheld the High Court's decision on the facts but disagreed with its interpretation of the "serious harm" test. Davis LJ held that the effect of section 1(1) was limited to raising the threshold of harm that must be met for a statement to be defamatory. Davis LJ also held that the phrase "is likely to cause" used in section 1(1) only denotes a "tendency" to cause, such that a claimant may rely on an inference of serious harm and is not necessarily required to prove serious harm on a balance of probabilities.

The defendants appealed to the Supreme Court on the proper interpretation of the "serious harm" requirement under section 1(1) of the 2013 Act.

Decision of the Supreme Court

Giving the unanimous judgment of the Supreme Court, Lord Sumption dismissed the appeal, albeit for reasons different from those of the Court of Appeal.

The court was clear that the 2013 Act had amended the common law on defamation to some degree. Under the common law on libel, there is a presumption that harm has been caused to the claimant's reputation – but no presumption that such harm is "serious". At the least, therefore, section 1(1) of the 2013 Act created a new statutory threshold of "serious harm".

The court went on to find that the application of the new threshold required a consideration of the actual consequences resulting from the defamatory statement, in addition to its inherent tendency to cause some harm to reputation.

In the court's reasoning, this was because the wording of section 1(1) – "has caused or is likely to cause" – points to a proposition of fact which can only be established by reference to the impact which the statement is shown actually to have had.

The Supreme Court also overturned the Court of Appeal's finding that the words "is likely to cause" in section 1(1) were a synonym for the inherent tendency which gives rise to the presumption of damage at common law. The Supreme Court found instead that past and future harm should both be treated as capable of being established as a fact.

The court also found support for its decision on section 1(1) in the wording of section 1(2) of the 2013 Act. Section 1(2) explains that, in relation to bodies trading for profit, the "serious harm" requirement imposed an obligation to show "serious financial loss". The court held that, reading these two provisions together, the draftsman must have intended for the question of harm to be determined by the consequences following publication.

In addition, the court affirmed the common law principles – all of which were unchanged by the 2013 Act – that:

  • a cause of action in libel is complete on publication, for limitation purposes; subsequent events may be regarded as evidence of the seriousness of the statement's impact but they do not have to have occurred before the cause of action has accrued;
  • the "repetition rule" which treats as defamatory the reporting of another person's statement; and
  • the Dingle rule that a defendant cannot rely in mitigation of damages on the fact that similar defamatory statements have been published about the same claimant by other persons.

Applying the "serious harm" threshold to the facts of Lachaux, the court nonetheless found that the words complained of were defamatory (for substantially the same reasons found by Warby J at first instance) and dismissed the appeal.


The decision shows that courts will be readily prepared to examine the factual impact of alleged defamatory statements. This new approach should mean that “serious harm” caused by defamation may be more difficult to prove for claimants seeking to pursue such a claim. Having said this, the Supreme Court made clear that a lack of evidence from those who had read the defamatory statements did not mean that the case must fail; it was sufficient to base the finding of “serious harm” on inferences of fact. As such, the impact of this decision in practice remains to be seen.

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