Jeevan Hariharan: The Changing Face of Horizontal Effect

On 10 March, Lord Sales delivered the Cambridge Freshfields Annual Law Lecture on the topic of ‘constitutional values in the common law of obligations’. The lecture, which has not been discussed so far on this blog, seeks to explain how constitutional values familiar from the world of public law (such as freedom of expression, liberty and access to justice) feature in private law areas such as tort and contract.

In the course of the speech, Lord Sales articulates a particular conception of how the European Convention on Human Rights (ECHR) relates to the way UK courts resolve disputes between private parties, an issue commonly referred to following the Human Rights Act 1998 (HRA) as ‘horizontal effect’. Lord Sales’ picture, which is summarised briefly below, is revealing because it offers an insight into how the Supreme Court, as currently constituted, seems to have shifted its approach in relation to horizontal effect. As I explain, the HRA’s horizontal effect was central in particular to the development of the English law of privacy. More recently, however, there is evidence of the court rejecting arguments based on the ECHR and HRA in the private law context. This can be understood as a continuation of a well-documented and controversial trend discernible in public law decisions, where the court has criticised the tendency to focus on the HRA and increasingly championed common law constitutional rights.

The long-standing debate about horizontal effect, and a clear example of the ECHR’s impact on private law

First, some background about horizontal effect. As is well known, the HRA imposes obligations on public authorities to act compatibly with ECHR rights (particularly via section 6(1)). However, section 6(3) makes it clear that domestic courts are themselves public authorities. And section 2 provides that a court or tribunal which is determining a question which has arisen in connection with an ECHR right must ‘take into account’ Strasbourg jurisprudence.

In the lead-up to the enactment of the HRA and its initial years in force, these provisions, among others, led to a preponderance of views about the nature and extent of the Act’s effect on disputes between private parties i.e. its ‘horizontal effect’. Clearly the Act would not have what has been called a ‘direct’ horizontal effect, because it does not impose obligations directly on private bodies. But authors disagreed about the extent of the Act’s ‘indirect’ horizontal impact. On one side, writers offered ‘strong’ accounts of indirect horizontal effect, by which the HRA would impose a duty on courts to interpret and apply existing laws compatibly with the ECHR (for example, Murray Hunt). Some commentators such as Sir Willian Wade QC even went as far as saying that courts would be obliged to create new causes of action to give effect to the ECHR. On the other side, there were ‘weaker’ conceptions of indirect horizontal effect, according to which courts would simply take account of the values represented by ECHR rights in their adjudication of private disputes (offered, for example, by Gavin Phillipson, though later reconsidered in a subsequent piece co-authored with Alexander Williams).

English courts have not reached any settled position on the horizontality issue. Indeed, as Mummery LJ noted in X v Y [2004] EWCA Civ 662 (at [45]), it may never be a question judicially resolved at the same level of abstraction as the academic debate. Nevertheless, particularly in the early years of the HRA, the ECHR clearly had a bearing on the development of domestic private law. The effects of the HRA were most keenly felt in the English law of privacy. In Campbell v MGN [2004] UKHL 22 (at [17]), Lord Nicholls famously said that the rights protected by Articles 8 and 10 of the ECHR had been ‘absorbed’ into breach of confidence (drawing on Lord Woolf CJ’s judgment in A v B plc [2002] EWCA Civ 337). Over time, English courts came to recognise that the ‘new’ form of breach of confidence was in fact a standalone tort, known as ‘misuse of private information’. The two-stage test for the misuse of private information action directly adopts the framework used to establish a claim against a public authority under Article 8. First, a court asks whether the information falls within the scope of the claimant’s private life. And second, on a proportionality analysis, the court considers whether the claimant’s privacy rights yield to other values, in particular the publisher’s Article 10 rights to freedom of expression (see e.g. McKennitt v Ash [2006] EWCA Civ 1714 at [11]).

While privacy is by far the clearest case of horizontal effect, this is not the only area of private law which has developed under the influence of the ECHR. In an important collection of essays published in 2011, the impact of the HRA on a number of aspects of private law was carefully reviewed, including substantive areas of law like defamation and nuisance, as well as issues concerning remedies and civil procedure. In all of these cases, it was concluded that the ECHR, through the HRA, had at least some effect on the domestic legal framework.

Lord Sales’ argument and the limited scope for ECHR impact

In the 2023 Freshfields lecture, Lord Sales offers an account of the relationship between constitutional values and private law which challenges a core premise of horizontal effect i.e. that the values enshrined in the ECHR are external to private law, and influence it from the outside. Lord Sales’ argument is that the adoption of the HRA, and the extensive commentary surrounding it, has perpetuated the perception that there is a divide between public law on the one hand, which is the proper home of constitutional values, and private law on the other. Historically, however, Lord Sales says that there was never such a strict division between public and private law, and that the values we have now come to understand as ‘human rights’ were already embedded within the common law of obligations. British lawyers, Lord Sales points out, were closely involved in the ECHR’s creation and drew on their understanding of English law in the drafting process. As such, there would have been nothing unsurprising to the English common lawyer about the rights the ECHR contained. Rather, the ECHR can be seen as a process of internationalising rights British subjects had long enjoyed.

Understood in this light, Lord Sales observes that the UK, even following the HRA, has not adopted a German-style approach whereby constitutional values have a ‘radiating’ or ‘totalising’ effect on the entire legal system, including private law. Instead, because the common law already reflects constitutional values, UK courts often do not need to have recourse to the ECHR in their adjudication. As an illustration of this in the private law context, Lord Sales draws on the recent decision of the Supreme Court in Fearn v Tate Gallery [2023] UKSC 4. This case concerned whether the operation of a viewing platform at the Tate Modern overlooking the claimants’ properties constituted an actionable nuisance. While the court was divided on the end result in Fearn (with Lord Sales himself dissenting and concluding there was no liability), the court was unanimous that Article 8 was an ‘unnecessary complication and distraction’ when determining the scope of the nuisance tort. Both the majority (at [113]) and minority (at [206]) held that visual intrusions were in principle actionable, and that this was a conclusion which could be reached on common law principles alone.

In the last part of the speech, Lord Sales qualifies this discussion by noting that there are nevertheless two limited circumstances where the ECHR can have an impact on private law. First, section 6 of the HRA can be a portal for the ECHR to influence the court’s resolution of private disputes, but only where ‘the common law has not considered the relevant rights and interests, or has signally failed to strike the appropriate balance’.

Second, and more indirectly, Lord Sales says that ECHR rights can play a legitimising role as ‘social propositions’ which guide the development of the common law. Lord Sales thinks that this second route may be the best way of explaining Campbell. On this view, the references to human rights standards in that case merely served the purpose of ‘unblocking a logjam’ in the common law development of privacy.

Evaluating the position

The picture Lord Sales offers us is one that champions the common law and sees the ECHR as having a limited role to play in private law adjudication, at least as an external reference point which can guide common law development. To many readers of this blog, well-versed with the court’s public law jurisprudence in recent years, this argument will reflect a familiar story. As has been well-documented, most notably in an excellent collection edited by Mark Elliott and Kirsty Hughes, there have been a number of UK Supreme Court decisions asserting the primary role of ‘common law constitutional rights’ while downplaying arguments based on the HRA. This includes cases like Osborn v Parole Board [2013] UKSC 61 where Lord Reed (at [57]) emphasised that the HRA does not supersede the protection of rights under common law or statute. Similarly in Kennedy v The Charity Commission [2014] UKSC 20, Lord Mance (at [46]) lamented the tendency to see areas of the law touched on by the ECHR solely in terms of ECHR rights, and Lord Toulson (at [133]) highlighted the importance of not overlooking the common law.

If it wasn’t clear beforehand, Lord Sales explicitly confirms that these observations in cases like Osborn and Kennedy are not limited to the public law sphere and apply equally in private law disputes. For counsel crafting arguments, the practical upshot will be all too clear. Submissions predicated on the ECHR will be relatively unlikely to find favour with this court. In this climate, it will usually be more strategic to argue that the common law already reflects a careful balance of values within it, rather than grounding arguments in the capacity of the common law to develop by reference to ECHR rights.

In terms of what we are to make of this position, three further thoughts are offered here. The first is that it is important to recognise that there has been a shift in relation to horizontal effect since the time the HRA came into force. As highlighted above, the horizontality issue has never been completely resolved by UK courts. At the same time, in the early years of the HRA, there was clearly a willingness to develop the common law by reference to ECHR rights, perfectly exemplified by the evolution of breach of confidence into a new tort of misuse of private information (a transformation put beyond doubt in Vidal-Hall v Google Inc [2015] EWCA Civ 311 where it was recognised that misuse of private information is a standalone tort). Lord Sales’ approach typifies a more cautious position, according to which the ECHR is seen to embody values which were already largely accommodated within the common law framework and thus plays a diminished role in actually influencing private law.

Despite what Lord Sales says, it seems very difficult to explain a decision like Campbell and subsequent developments in privacy law within the highly limited account of horizontal effect he offers. Even if it is true that privacy protection had long been lamented in English courts, the ECHR seems to have done far more in this area than simply unblock a logjam in the common law. Indeed, the specific way that misuse of private information developed was clearly one that placed the ECHR framework front-and-centre. This is particularly true of the two-stage test, which is centrally guided by the structure and content of Articles 8 and 10 (see e.g. the articulation of the test in McKennitt, referred to above). To say now that the human rights standards referred to in early post-HRA privacy cases are merely broad social propositions seems to underplay the role of the ECHR in this area quite significantly. And it disguises the fact that there has been an important shift in the current Supreme Court’s approach to the ECHR.

The second point to highlight is that Lord Sales says little to substantiate his account of the precise circumstances where the ECHR can have an impact on private disputes via the HRA. In the speech, as already mentioned, Lord Sales contends that section 6 of the HRA creates a limited portal for the ECHR to have effect when the common law has ‘signally failed’ to accommodate human rights standards in an acceptable manner. But there is no further elaboration as to what the term ‘signal failure’ means nor any specific examples provided of where it has come into play, and thus little clarity about what threshold has to be met before the ECHR can be invoked.

As an illustration of some of the uncertainties with the ‘signal failure’ threshold, it is worth considering the Supreme Court’s recent decision in Fearn. This is the case Lord Sales cites as an example where recourse to the ECHR was not required, because the tort of private nuisance already appropriately accommodates privacy interests and has always had the capacity to protect against visual intrusions. One of the striking points about Fearn, however, is that it was far from a situation where the scope of the action was well-settled at common law prior to the decision. Indeed, the Court of Appeal had unanimously come to the opposite conclusion to the Supreme Court, holding that the weight of judicial authority pointed in the direction that nuisance cannot protect against overlooking. And there had certainly been no reported case in the UK prior to the Supreme Court’s judgment which authoritatively confirmed that visual intrusions could constitute a nuisance at common law.

In such circumstances, one can wonder why Fearn was a case where the ‘signal failure’ threshold had not been met. Moreover, even if the common law of nuisance had not ‘failed’ to protect privacy per se, surely this was precisely the type of situation where it would have been beneficial to at least consider the ECHR position rather than viewing it as an ‘unnecessary complication and distraction’. That, as it turns out, had been the exact approach of Mann J in the High Court at first instance (whose judgment Lord Sales in other respects endorsed). Mann J said that, had it been necessary to do so, he would have concluded that the ‘tort of nuisance, absent statute, would probably have been capable, as a matter of principle, of protecting privacy rights, at least in a domestic home’ (see at [169]). But the position was put beyond doubt by the HRA and the ECHR, given that Article 8 clearly protects against external prying (see [170]-[174]). In other words, Mann J did not see the ECHR as only being applicable through the HRA where there had been a ‘signal failure’. Rather, and arguably far more consistently with earlier privacy jurisprudence, the ECHR was viewed as complementing the common law reasoning process.  

Linked to the point about uncertainties with the ‘signal failure’ threshold, the third and final comment made here is a wider concern about the way in which Lord Sales’ approach to constitutional values arguably opens the door to unprincipled and unpredictable reasoning in future cases. To be clear, the difficulty here is not with the idea that constitutional values (such as private life, liberty and freedom of expression) are enmeshed within the common law of obligations. The issue is that these values have rarely, if ever, been defined with a level of precision in the common law in a way which allows them to guide adjudication in a consistent or dependable manner, at least when compared to the ECHR and its well-developed jurisprudence.

In the opening chapter of their collection on common law constitutional rights, Elliott and Hughes draw out a similar point, identifying that common law constitutional rights can be more subject to ‘judicial preferences’ compared to ECHR rights. Such comments are highly apposite when considering the role of constitutional values in the private law context. If the Supreme Court is going to go down the route of saying, as Lord Sales does in relation to Fearn, that torts like private nuisance can be understood by reference to underlying values like privacy but without recourse to the ECHR, much more clarity is arguably needed on what we mean by privacy as a constitutional value. And the same goes for other constitutional values as well, otherwise there is a risk of a high degree of uncertainty about how far certain aspects of our private law extend, driven by different judicial attitudes about the nature and influence of the constitutional values underlying them.

I am grateful to Michael Gordon, Colm O’Cinneide, Aarushi Sahore and Paul Scott for helpful comments.

Dr Jeevan Hariharan is a Lecturer in Private Law at Queen Mary University of London.

(Suggested citation: J. Hariharan, ‘The Changing Face of Horizontal Effect’, U.K. Const. L. Blog (17th May 2023) (available at