Jeremy Letwin: The Bill of Rights Bill and the Modern Mirror Principle

The Bill of Rights Bill which is currently before Parliament aims, at least in some respects, to weaken the link between domestic courts and the ECtHR. Many predicted the Bill might seek to do this, and it has provoked considerable controversy. Though clauses 3(1) and 3(2) of the Bill are not without their critics, the controversy has mainly focused on clause 3(3)(b), which provides that the domestic courts “may adopt an interpretation of the right that diverges from Strasbourg jurisprudence”, and on clause 3(3)(a), which provides that domestic courts “may not adopt an interpretation of the right that expands the protection conferred by the right unless the court has no reasonable doubt that the European Court of Human Rights would adopt that interpretation if the case were before it”. 

The Bill’s critics are divided about whether clause 3 would have any real impact. Lord Mance has commented that clause 3 of the Bill “would in reality do little more than restate existing law”. But this view is not shared by the JCHR, which has remarked that “the approach currently taken by the domestic courts … is a long way from requiring there be no reasonable doubt as to Strasbourg’s interpretation”. 

This raises the question, how different is clause 3 from the ‘modern mirror principle’ which has developed as a way of giving effect to s.2 HRA? Would it mean any real change from the status quo? Although the Government appears to have ‘deprioritised’ the Bill and its future is now uncertain, these questions nevertheless remain important ones. If the Bill advances in its passage, then any attempts to amend it will need to take into account the effect that it would have, in its current form, on the law as it is today. And even if the Bill perpetually flounders on the rocks, understanding its potential effects provides an interesting window into the current state of the mirror principle. 

Clause 3(3)(b): Giving Less Generous Protection to Convention Rights Than Strasbourg?

The law today has moved a considerable distance from the mirror principle as it was originally expounded by Lord Bingham in UllahDomestic courts have, as Lewis Graham observes, gradually “adopted a much more assertive stance in relation to Strasbourg, and … more readily refused to follow its case law”. Though this transition has not been entirely smooth, for the time being at least, the position seems to be that there is a wide range of circumstances in which domestic courts may give less protection than does the ECtHR to Convention rights, including where ECtHR judgments are considered incorrect or are likely to have negative consequences domestically. 

However, unless the Bill intervenes, the mirror principle seems likely to continue to develop organically. As their dissenting judgments in McLaughlin and Hallam show, Lords Hodge and Reed (the Deputy President and the President) have little enthusiasm for departing from ECtHR jurisprudence simply on the grounds that it is considered incorrect or would have negative consequences domestically. And all four of the judges who were the main drivers of the more assertive stance (Lords Hughes, Carnwath, Wilson and Mance) have now retired from the Supreme Court. 

There is also currently an unresolved tension in the domestic case law about how “clear and constant” Strasbourg jurisprudence must be for domestic courts to regard themselves as effectively bound (absent special circumstances) to follow Strasbourg. In cases like Alconbury and Amin the Court adopted a relatively deferential approach to dialogue with Strasbourg. In cases like AF (No 3) and Chester, by contrast, the Court took a less deferential approach – implying that domestic courts should feel bound by Strasbourg only where (as Lord Sumption put it in Chester) there was “no realistic prospect that further dialogue with Strasbourg [would] produce a change of heart”. 

Clause 3(3)(b) would, if passed, resolve these tensions in favour of the permissive approach to divergence from Strasbourg adopted in McLaughlin/Hallam, and in favour of the assertive stance to dialogue with Strasbourg adopted in AF (No 3)/Chester. Whereas, without it, there would still be potential for the Supreme Court to return to something closer to the original, stricter mirroring envisaged in Ullah. Indeed, a court interpreting substantive provisions of the Bill which are evidently intended to diminish the protection of Convention rights (such as clauses 14 and 20) might feel empowered by clause 3(3)(b) to reach outcomes which directly conflict with settled Strasbourg jurisprudence. Whereas, without clause 3(3)(b), the courts would be more likely to ‘read down’ such substantive provisions so as to make them compatible with Strasbourg jurisprudence. 

However, the Bill does not, of course, affect the UK’s membership of the Council of Europe. The courts are thus likely, as ever, to remain mindful of the UK’s obligations under international law, to retain the underlying presumption that domestic jurisprudence should mirror ECtHR jurisprudence, and to follow ECtHR jurisprudence in protecting rights whenever there is no realistic prospect of further dialogue with Strasbourg. Accordingly, the Bill (even if enacted in its current form) seems unlikely to have any truly radical downward effect on the protection of Convention rights.

Clause 3(3)(a): Giving More Generous Protection to Convention Rights Than Strasbourg?

Since Ullah, there has also been a healthy judicial debate about how far domestic courts should be permitted to give more generous protection to Convention rights than Strasbourg. More permissive approaches have sometimes been prominent (e.g. Ullah, EM (Lebanon)Limbuela, Re Gand Nicklinson). At other times, more restrictive approaches have come to the fore (e.g. Al-Skeini).

At present, the more restrictive approach seems to have won the day. In the recent judgment of ABLord Reed held that the courts should not “establish new principles of Convention law”. However, Lord Reed recognised that in “situations which have not yet come before the European court, they can and should aim to anticipate, where possible, how the European court might be expected to decide the case”, and that in such cases “some incremental development” of the ECtHR’s jurisprudence “may be involved”. Similar comments were made by Lord Reed in Elan-Cane, when he endorsed the statement in Moohan that such development can occur where it “flows naturally from Strasbourg’s existing case law”. 

The question, then, is whether the JCHR is right to claim that the current case law – which permits domestic courts to give more generous protection to Convention rights than Strasbourg where such protection “incrementally develops” and  “flows naturally” from the Strasbourg jurisprudence – is “a long way” from the Bill’s stipulation that domestic courts may only “expand” the protection conferred by a right where there is “no reasonable doubt that the European Court of Human Rights would adopt that interpretation if the case were before it”?

There are two plausible interpretations of the phrase “expands the protection conferred by the right”: 

(1.1) expands compared to existing domestic case law; or,

(1.2) expands compared to existing ECtHR case law. 

There are also at least three plausible understandings of the phrase “no reasonable doubt that the European Court of Human Rights would adopt that interpretation if the case were before it”: 

(2.1) “No reasonable doubt” might be understood literally, as meaning something like “close to certainty” or “being sure”. 

(2.2) As Verdirame suggests, because of the high threshold set by “no reasonable doubt” the courts might instead focus on the second part of the phrase. Cases only come “before” Strasbourg if they are “arguable”.  Any case which is “arguable” is by definition one where there will be “reasonable doubt” about the outcome.  And so arguability might replace “reasonable doubt” as the threshold – if there is an arguable case against an expansive reading of the Convention the courts will have to reject it, and only if there is no arguable case against an expansive reading may the courts accept it.

(2.3) “No reasonable doubt” might be taken to refer in this context simply to a generic high threshold, rather than to its ordinary language meaning of near-certainty. 

At the most radical end of the spectrum – if “expands” was taken to mean “expands compared to existing domestic case law” (option 1.1) and “no reasonable doubt” was understood literally (option 2.1) – clause 3(3)(a) could have the effect of compelling the courts to reject any claim for the violation of a Convention right unless there were existing domestic cases directly in point, or a string of multiple Grand Chamber judgments clearly determining the issue. 

Even at the most conservative end of the spectrum – if “expands” was taken to mean “expands compared to existing ECtHR case law” (option 1.2) and “no reasonable doubt” was understood to be nothing more than a generic high threshold (option 2.3) –  then clause 3(3)(a) would surely still represent a change to the status quo. It is difficult to see how even a highly conservative interpretation of the phrase “no reasonable doubt” could make it equate to the current test of whether an expansion of rights “flows naturally” from the Strasbourg jurisprudence. The phrase, “flow naturally”, is, of course, itself open to interpretation, and the courts have never explicitly equated it to any specific threshold of certainty expressed in probabilistic terms. However, in EM(Lebanon) and Limbuela (as Lady Hale commented in 2011) the Supreme Court went “further than Strasbourg had gone at the time and probably further than Strasbourg would still go”. And these cases have not yet been overruled or disapproved. So, although the phrase “flow naturally” could, at least in theory, be equated with a conservative interpretation of the “no reasonable doubt” threshold in the Bill, in practice, the way the courts have applied the phrase means that it requires no more than it being likely, on the balance of probabilities, that the ECtHR would reach that result (indeed, arguably even less certainty than this might suffice). 

So the JCHR is correct that clause 3(3)(a) is a long way from the law as it stands today. Exactly how far, depends on how the courts interpret the clause if and when it enters the statute books. But even a court straining to align the interpretation of clause 3(3)(a) with the AB/Elan-Cane approach would be forced to conclude that clause 3(3)(a) significantly diminishes the power of domestic courts to expand Convention rights by engaging in evolutive interpretation of the Convention.

Dr Jeremy Letwin, Visiting Lecturer in Law at KCL.

(Suggested citation: J. Letwin, ‘The Bill of Rights Bill and the Modern Mirror Principle’, U.K. Const. L. Blog (14th March 2023) (available at