¹ This is apparent in Lord Carnwath's characterisation of the issue in R. (N) v London Borough of Lewisham [2014] UKSC 62, [2015] A.C. 1259, at [94]: “the debate … is about two important but sometimes conflicting principles – legal correctness and legal certainty. In drawing the balance between them, as in most areas of the law, pragmatism and indeed common sense have a legitimate part to play.”

² E.g. in Campbell College, Belfast v Valuation Commissioner for Northern Ireland [1964] 1 W.L.R. 912, 941 (H.L.). For discussion of the confused use of terminology in this area, including in that case, see Hurst, D.J., “The Problem of the Elderly Statute” (1983) 3 L.S. 21, 23–29Google Scholar.

³ [2009] EWCA Civ 94, [2010] Q.B. 163.

⁴ Ibid.

⁵ Ibid., at [43]–[44].

⁶ E.g. R. (N) v London Borough of Lewisham [2014] UKSC 62, at [53] (Lord Hodge), [95] (Lord Carnwath); Millan v T Leith Developments Ltd. [2017] CSIH 23, at [68] (Lord Carloway); Campbell College, Belfast v Valuation Commissioner [1964] 1 W.L.R. 912, 941 (Lord Upjohn); Clyde Navigation (Trustees of) v Laird & Sons (1883) 8 App. Cas. 658, 673 (Lord Watson). For earlier authorities to like effect, see Craies, W.F., Statute Law, 2nd ed. (London 1911), 154–55Google Scholar.

⁷ West Ham Union v Edmonton Union [1908] A.C. 1, 4–5 (Lord Loreburn L.C.).

⁸ Keyes, J.M. and Diamond, C., “Constitutional Inconsistency in Legislation – Interpretation and the Ambiguous Role of Ambiguity” (2017) 48 Ottawa L. Rev. 319, 327Google Scholar.

⁹ Campbell College, Belfast v Valuation Commissioner [1964] 1 W.L.R. 912, 941 (Lord Upjohn). As noted above, while reference is made in that case to the doctrine of contemporary exposition, what in fact seems to be under consideration is long usage. See Hurst, “Problem of the Elderly Statute”, 23–29.

¹⁰ (1883) 8 App. Cas. 658, 673. The point made in the previous footnote about the confused terminology is equally applicable to Lord Watson's judgment in this case.

¹¹ Ibid., at 670.

¹² Rittson-Thomas v Oxfordshire County Council [2021] UKSC 13, [2021] 2 W.L.R. 993, at [35] (Lady Arden and Lord Burrows).

¹³ [2009] EWCA Civ 94, at [43]. Carnwath L.J. also refers to R. (Jackson) v Attorney General [2005] UKHL 56, [2006] 1 A.C. 262, at [68]–[69] (Lord Nicholls), [171] (Lord Carswell), to support this view.

¹⁴ [2011] UKSC 25, [2011] 1 W.L.R. 1546.

¹⁵ Ibid., at [58].

¹⁶ R. (N) v London Borough of Lewisham [2014] UKSC 62, [2015] A.C. 1259, at [95] (Lord Carnwath). For the use of subsequent legislative practice, see R. (Jackson) v Attorney General [2005] UKHL 56, at [69] (Lord Nicholls), [171] (Lord Carswell), and Isle of Anglesey County Council v Welsh Ministers [2009] EWCA Civ 94, [2010] Q.B. 163, at [39], [44] (Carnwath L.J.), [84] (Pill L.J.).

¹⁷ Reliance on government conduct in interpreting subordinate legislation that has been made by ministers and drafted by government officials should perhaps be viewed with particular scepticism in this regard.

¹⁸ [1919] A.C. 815.

¹⁹ Ibid., at 857.

²⁰ Ibid., at 874.

²¹ Ibid. (Lord Buckmaster).

²² See generally Bailey, D. and Norbury, L., Bennion, Bailey and Norbury on Statutory Interpretation, 8th ed. (London 2020), section 24.4Google Scholar.

²³ For an earlier, particularly strong, example of reliance on settled practice, see Hanau v Ehrlich [1912] A.C. 39, 41 (Earl Loreburn L.C.).

²⁴ Black-Clawson International Ltd. v Papierwerke Waldhof-Aschaffenberg A.G. [1975] A.C. 591, 637 (Lord Diplock).

²⁵ Sales, P., “Modern Statutory Interpretation (2017) 38 Stat. L.R. 125, 130Google Scholar.

²⁶ [2005] UKHL 56.

²⁷ Ibid., at [69]. Despite the dicta cited here, it is suggested that the settled practice relied on in Jackson was too remote from the interpretative question to be particularly illuminating. It seems a stretch to characterise general acceptance of the 1949 Act amendments as indicative of a settled practice in relation to the interpretation of the 1911 Act.

²⁸ Ibid., at [171].

²⁹ Ibid., at [68] (Lord Nicholls), [171] (Lord Carswell).

³⁰ E.g. R. (Spath Holme Ltd.) v Secretary of State for the Environment, Transport and the Regions [2001] 2 A.C. 349, 388D (Lord Bingham). See also the collection of materials discussed in Ekins, R. and Goldsworthy, J. “The Reality and Indispensability of Legislative Intentions” (2014) 26 Sydney L. Rev. 39, 39–41Google Scholar.

³¹ Sales, P., “Legislative Intention, Interpretation, and the Principle of Legality” (2019) 40 Stat. L.R. 53, 58Google Scholar.

³² R. (Spath Holme Ltd.) v Secretary of State for the Environment, Transport and the Regions [2001] 2 A.C. 349, 396G (Lord Nicholls).

³³ See e.g. Burrows, A., Thinking About Statutes: Interpretation, Interaction, Improvement (Cambridge 2018), 17–19CrossRefGoogle Scholar, who proposes focussing on “purpose” rather than “intention”.

³⁴ See e.g. Dworkin, R., Law's Empire (Cambridge, MA 1986)Google Scholar, 313–54; Waldron, J., Law and Disagreement (Oxford 1999), 119–46CrossRefGoogle Scholar.

³⁵ Ekins, R., The Nature of Legislative Intent (Oxford 2012), 13, 112–13CrossRefGoogle Scholar.

³⁶ On the nature of these interpretative choices and the framework within which they are made, see J. Dharmananda, “Certainty, Choice and Text in Statutory Interpretation” in J. Barnes (ed.), The Coherence of Statutory Interpretation (Sydney 2019), ch. 11, 118.

³⁷ R. Ekins, “Statutes, Intentions and the Legislature: A Reply to Justice Hayne” (2014) 14 O.U.C.L.J. 3, 6. Cited with approval in P. Sales, “In Defence of Legislative Intention” (Lincoln's Inn 2019), available at https://www.lincolnsinn.org.uk/wp-content/uploads/2020/11/2019-Denning-Society-Lecture-In-Defence-of-Legislative-Intention.pdf (last accessed 19 July 2021), on which this paragraph draws more generally.

³⁸ [2014] EWHC 1918, [2015] 1 All E.R. 165, at [65].

³⁹ R. (Westminster City Council) v National Asylum Support Service [2002] UKHL 38, [2002] 1 W.L.R. 2956, at [5] (Lord Steyn). See also A-G v Prince Ernest of Hanover [1957] A.C. 436, 461 (Viscount Simonds).

⁴⁰ See generally Bailey and Norbury, Statutory Interpretation, section 11.2 (text of enactment to be read in context).

⁴¹ [2005] UKHL 41, [2005] 2 A.C. 680, at [38]. See also R. (N) v London Borough of Lewisham [2014] UKSC 62, at [167] (Lady Hale: “Parliament's failure to act tells us nothing about what Parliament intended when the legislation was passed, which is what this court must decide”).

⁴² Ekins and Goldsworthy “Reality and Indispensability of Legislative Intentions”, 58.

⁴³ [1877] 2 App. Cas. 743, 763.

⁴⁴ R. v G [2003] UKHL 50, [2004] 1 A.C. 1034, at [29] (Lord Bingham: “Since a statute is always speaking, the context or application of a statutory expression may change over time, but the meaning of the expression itself cannot change”). See also J. Goldsworthy, “Lord Burrows on Legislative Intention, Statutory Purpose, and the ‘Always Speaking’ Principle” (2022) Stat. L.R. 79.

⁴⁵ R. (on the application of ZYN) v Walsall Metropolitan Borough Council [2014] EWHC 1918 (Admin), [2015] 1 All E.R. 165, at [45] (Leggatt J.).

⁴⁶ For recent examples, see Isle of Anglesey v Welsh Ministers [2009] EWCA Civ 94, at [43] (Carnwath L.J.); Bloomsbury International Ltd. v Sea Fish Industry Authority [2011] UKSC 25, [2011] 1 W.L.R. 1546, at [57]–[58] (Lord Phillips); R. (N) v London Borough of Lewisham [2014] UKSC 62, at [94] (Lord Carnwath).

⁴⁷ Raz, J., “The Rule of Law and Its Virtue” in Raz, J. (ed.), The Authority of Law: Essays on Law and Morality (Oxford 2009), 214Google Scholar.

⁴⁸ A variant of this argument may be found in Lady Hale's observations in R. (N) v London Borough of Lewisham [2014] UKSC 62, at [168].

⁴⁹ Isle of Anglesey v Welsh Ministers [2009] EWCA Civ 94, at [43].

⁵⁰ [1919] A.C. 815.

⁵¹ Ibid., at 874. See also Campbell College, Belfast v Valuation Commissioner [1964] 1 W.L.R. 912, 918 (Lord Reid), 930–31 (Viscount Radcliffe).

⁵² [2014] UKSC 62, at [94].

⁵³ I am grateful to Professor David Feldman for pointing this out to me.

⁵⁴ D. Bailey, “Interpreting Parliamentary Inaction” [2020] C.L.J. 245.

⁵⁵ Wilson v First Country Trust [2003] UKHL 40, [2004] 1 A.C. 816, at [67] (Lord Nicholls).

⁵⁶ Feldman, D., “Statutory Interpretation and Constitutional Legislation” (2014) 130 L.Q.R. 473, 481Google Scholar; Goldsworthy, J., Parliamentary Sovereignty: Contemporary Debates (Cambridge 2010), 232CrossRefGoogle Scholar.

⁵⁷ The general principle of construction is often referred to as “the Barras Principle” after Barras v Aberdeen Sea Trawling and Fishing Co. Ltd. [1933] A.C. 402. For relatively recent statements as to the breadth of its application, see Norman v Cheshire Fire & Rescue Service [2011] EWHC 3305 (Q.B.), at [52] (Andrew Smith J.: the principle “is not confined to statements of law made by way of binding precedent”); R. v Chief Constable of the Royal Ulster Constabulary, ex parte Begley [1997] 1 W.L.R. 1475, 1481 (Lord Browne-Wilkinson relying on the “clear statement of the prevailing view and practice in Northern Ireland” evidenced by an official report).

⁵⁸ [1891] A.C. 531, 591.

⁵⁹ IRC v Dowdall, O'Mahoney & Co. Ltd. [1952] A.C. 401, 426 (Lord Radcliffe).

⁶⁰ See Cape Brandy Syndicate v Inland Revenue Commissioners [1921] 2 K.B. 403. See further Bailey and Norbury, Statutory Interpretation, section 24.19.

⁶¹ See also R. (N) v London Borough of Lewisham [2014] UKSC 62, at [95] (Lord Carnwath: “[the settled practice principle] should not necessarily depend on the degree or frequency of Parliamentary interventions in the field.”).

⁶² The doctrine, traditionally expressed in the Latin maxim contemporanea expositio est optima et fortissinia in lege, is referred to several times by Coke in the Institutes. See e.g. 2 Co. Inst. 11. The doctrine is also sometimes referred to in the abbreviated form contemporanea expositio.

⁶³ P. St. J. Langan, Maxwell on The Interpretation of Statutes, 12th ed. (London 1969), 264. The passage in an earlier edition of that book was approved by the Court of Criminal Appeal in R. v Casement [1917] 1 K.B. 98, 138. It is also cited by Bell, J. and Engle, G., Cross on Statutory Interpretation, 3rd ed. (London 1995), 137Google Scholar; and Bennion, F., Bennion on Statutory Interpretation, 5th ed. (London 2008), 913Google Scholar.

⁶⁴ [1889] 14 P.D. 34, 36. See also Sharpe v Wakefield (1888) 22 Q.B.D. 239, 241 (Lord Esher).

⁶⁵ For further examples see Meagher, D., “The Principle of Legality and Contemporanea Exposition est Optima et Fortissima in Lege” (2017) 38 Stat. L.R. 98, 101Google Scholar.

⁶⁶ R. (Quintavalle) v Secretary of State for Health [2003] UKHL 13, [2003] 2 A.C. 687, at [9] (Lord Bingham).

⁶⁷ Hurst, “Problem of the Elderly Statute”, 24, 30.

⁶⁸ [2011] UKSC 25.

⁶⁹ Ibid., at [61].

⁷⁰ If the interpretation endures it may form part of the body of evidence that the interpretation is a sound one. This justification for the use of settled practice is discussed below.

⁷¹ For discussion in the US, see Healy, M.P., “Communis Opinio and the Method of Statutory Interpretation: Interpreting Law or Changing Law” (2001) 43 Wm. & Mary L. Rev. 539, 583Google Scholar.

⁷² Hart, H.M. and Sacks, A.M., The Legal Process: Basic Problems in the Making and Application of Law, edited by Eskridge, W.N. and Frickey, P.P. (New York 1994), 1379, 1270Google Scholar.

⁷³ For the need to have regard to consequences when approaching questions of interpretation, see Bailey and Norbury, Statutory Interpretation, section 11.6.

⁷⁴ Goldsworthy, Parliamentary Sovereignty, 247.

⁷⁵ [2014] UKSC 62, at [148]; see also at [168] (Lady Hale).

⁷⁶ While settled practice is more likely to have relevance in relation to older Acts, I am not advocating that antiquity should be viewed as a threshold test for the use of settled practice (see Section II above).