Published online by Cambridge University Press: 07 December 2020
This article examines the principle of legality, a principle of statutory interpretation that requires clear statutory words to oust basic common-law norms. The principle is of growing importance in the Supreme Court's public law jurisprudence, yet it has garnered little scholarly attention. This article offers a comprehensive account of the principle, unpacking its core elements and identifying key controversies. The article reveals that lying beyond this apparently straightforward principle is a complex and elaborate jurisprudence, which raises fundamental issues of principle, policy and judicial legitimacy.
Professor of Law, Melbourne Law School, University of Melbourne.
I am especially grateful to Rick Rawlings with whom I have shared a number of stimulating discussions on the issues addressed herein. I also wish to thank Mark Aronson, Andrew Burrows, Tom Hickman and Nick Petrie for helpful discussions and/or comments on drafts, and the two anonymous reviewers for valuable comments. Drafts of this article were presented at a Centre for Public Law Seminar, University of Cambridge, November 2019, a Research Seminar at the Bonavero Institute of Human Rights, University of Oxford, November 2019, and a Public Law Group Workshop at UCL, December 2019. I am grateful to participants at each event for very helpful discussions. The bulk of this article was written during Michaelmas Term 2019 while I was the Robert S. Campbell Visiting Fellow in Law at Magdalen College, Oxford, and a Research Visitor at the Bonavero Institute of Human Rights. The usual disclaimer applies.
1 R. (Unison) v Lord Chancellor [2017] UKSC 51, [2017] 3 W.L.R. 409.
2 R. (Cherry) v Advocate General for Scotland [2019] UKSC 41, [2020] A.C. 373.
3 See e.g. R. v Secretary of State for the Home Department, ex parte Stafford [1999] 2 A.C. 38, 47–49; R. v Lord Chancellor, ex parte Lightfoot [2000] Q.B. 597, 607–10, 623–24; R. (Child Poverty Action Group) v Secretary of State for Work and Pensions [2010] UKSC 54, [2011] 2 A.C. 15, at [31]. Even if the PoL is not enlivened, for example because the common-law norms at stake are not considered normatively weighty enough to trigger the legality principle, a weaker presumption in favour of preservation of common-law norms may nonetheless apply: Burrows, A., Thinking About Statutes (Cambridge 2018), 71–74CrossRefGoogle Scholar.
4 See e.g. Ledwith v Roberts [1937] 1 K.B. 232, 255 (liberty); Commissioner of Public Works (Cape Colony) v Logan [1903] A.C. 355, 363–64 (land); Metropolitan Asylum District v Hill (1881) 6 App. Cas. 193 (enjoyment of land); Newcastle Breweries Ltd. v The King [1920] 1 K.B. 854, 866 (goods); Allen v Gulf Oil Refining Ltd. [1981] A.C. 1001 (enjoyment of land); Morris v Beardmore [1981] A.C. 446, 455, 461–65 (land).
5 See Varuhas, J.N.E., “Administrative Law and Rights in the UK House of Lords and Supreme Court” in Daly, P. (ed.), Apex Courts and the Common Law (Toronto 2019), 241–54Google Scholar; Lazarus, L., Contrasting Prisoners’ Rights: A Comparative Examination of England and Germany (Oxford 2004)CrossRefGoogle Scholar, ch. 7.
6 R. v Board of Visitors of Hull Prisons, ex parte St Germain [1979] Q.B. 425, 455.
7 Raymond v Honey [1983] A.C. 1.
8 E.g. Golder v U.K. (1979–80) 1 E.H.R.R. 524; Silver v U.K. (1983) 5 E.H.R.R. 347.
9 R. v Secretary of State for the Home Department, ex parte Brind [1991] 1 A.C. 696, 748, 762.
10 See Varuhas, “Administrative Law and Rights”. And see e.g. R. Masterman and S. Wheatle, “Unity, Disunity and Vacuity: Constitutional Adjudication and the Common law” in M. Elliott, J.N.E. Varuhas and S.W. Stark (eds.), The Unity of Public Law (Oxford 2018); M. Elliott and K. Hughes (eds.), Common Law Constitutional Rights (Oxford 2020).
11 E.g. R. v Secretary of State for the Home Department, ex parte Simms [2000] 2 A.C. 115.
12 E.g. R. (Unison) v Lord Chancellor [2017] UKSC 51.
13 See e.g. D. Feldman, “Civil Liberties” in V. Bogdanor (ed.), The British Constitution in the Twentieth Century (Oxford 2003); W.I. Jennings, The Law and the Constitution, 5th ed. (London 1959), 262–63; J.N.E. Varuhas, “The Reformation of English Administrative Law?” [2013] C.L.J. 369, 402–06; D. Meagher, “Is There a Common Law ‘Right’ to Freedom of Speech?” (2019) 43 M.U.L.R. 269.
14 R. v Lord Chancellor, ex parte Witham [1998] Q.B. 575, 585, emphasis added, and see 581.
15 Watkins v Secretary of State for the Home Department [2006] UKHL 17, [2006] 2 A.C. 395.
16 R. v Secretary of State for the Home Department, ex parte Pierson [1998] A.C. 539, 585–92, 603–04.
17 R. (Evans) v Attorney General [2015] UKSC 21, [2015] A.C. 1787, at [52].
18 R. (Privacy International) v Investigatory Powers Tribunal [2019] UKSC 22, [2020] A.C. 491.
19 R. (Cherry) v Advocate General [2019] UKSC 41, at [47].
20 E.g. Shahid v Scottish Ministers [2015] UKSC 58, [2016] A.C. 429; R. (Johnson) v Secretary of State for the Home Department [2016] UKSC 56, [2017] A.C. 365; SXH v CPS [2017] UKSC 30, [2017] 1 W.L.R. 1401; SS (Congo) v Entry Clearance Officer, Nairobi [2017] UKSC 10, [2017] 1 W.L.R. 771; Application by the Northern Ireland Human Rights Commission for Judicial Review [2018] UKSC 27, [2019] 1 All E.R. 173; R. (Steinfeld) v Secretary of State for International Development [2018] UKSC 32, [2020] A.C. 1.
21 R. (Gillan) v Commissioner of Police for the Metropolis [2006] UKHL 12, [2006] 2 A.C. 307, at [1], [15].
22 Other cases adopt similarly minimal reasoning for rejecting norms as triggers: e.g. R. v Secretary of State for the Home Department, ex parte Stafford [1999] 2 A.C. 38, 47–49.
23 R. (Osborn) v Parole Board [2013] UKSC 61, [2014] A.C. 1115, at [54]–[63].
24 E.g. R. v Secretary of State for the Home Department, ex parte Simms [2000] 2 A.C. 115, 131–32; Pham v Secretary of State for the Home Department [2015] UKSC 19, [2015] 1 W.L.R. 1591, at [106]; Kennedy v Information Commissioner [2014] UKSC 20, [2015] A.C. 455, at [46].
25 Campbell v MGN Ltd. [2004] UKHL 22, [2004] 2 A.C. 457.
26 Cf. R. (Gallaher Group Ltd.) v Competition and Markets Authority [2018] UKSC 25, [2019] A.C. 96.
27 R. (Unison) v Lord Chancellor [2017] UKSC 51, at [66]–[73].
28 R. v Secretary of State for the Home Department, ex parte Simms [2000] 2 A.C. 115, 125–27.
29 The necessity of developing criteria is recognised by some senior judges: P. Sales, “Rights and Fundamental Rights in English Law” (2016) 75 C.L.J. 86.
30 Elgizouli v Secretary of State for the Home Department [2020] UKSC 10, [2020] 2 W.L.R. 857.
31 Ibid., at [191]–[203].
32 Text to notes 52–54 below.
33 Elgizouli v Secretary of State for the Home Department [2020] UKSC 10, at [147] (Lord Kerr dissenting).
34 Ibid., at [197]–[198]; Chahal v U.K. (1997) 23 E.H.R.R. 413.
35 See Lord Kerr's survey in dissent: ibid., at [107]–[134], and see [189].
36 Ibid., at [194]–[195], [205], [232]–[233].
37 See ibid., at [105] (Lord Kerr dissenting).
38 Ibid., at [171], [175], [191], [193]–[194].
39 Ibid., at [172], [175], and see [234].
40 Attorney General v Guardian Newspapers Ltd. (No. 2) [1990] 1 A.C. 109, 282–284.
41 Elgizouli v Secretary of State for the Home Department [2020] UKSC 10, at [175].
42 Text to notes 10–15 above.
43 Elgizouli v Secretary of State for the Home Department [2020] UKSC 10, at [14].
44 E.g. R. (Evans) v Attorney General [2015] UKSC 21; R. (Privacy International) v Investigatory Powers Tribunal [2019] UKSC 22.
45 R. (Cherry) v Advocate General [2019] UKSC 41, at [40], [46].
46 Ibid.
47 R. (Miller) v Secretary of State for Exiting the European Union [2017] UKSC 5, [2018] A.C. 61, at [136]–[151].
48 AXA General Insurance Company Ltd. v Lord Advocate [2011] UKSC 46, [2012] 1 A.C. 868, at [153]; R. v Secretary of State for the Home Department, ex parte Pierson [1998] A.C. 539, 573, 587.
49 R. (Miller) v Secretary of State for Exiting the European Union [2017] UKSC 5, at [151].
50 R. (Evans) v Attorney General [2015] UKSC 21, at [52].
51 R. v Secretary of State for the Home Department, ex parte Pierson [1998] A.C. 539, 585–92, 603–04.
52 R. (Unison) v Lord Chancellor [2017] UKSC 51, at [65].
53 Ibid., at [96]–[97].
54 Ibid., at [91].
55 R. v Secretary of State for the Home Department, ex parte Pierson [1998] A.C. 539, 576, 578–79.
56 Ibid., at 575–76; Elgizouli v Secretary of State for the Home Department [2020] UKSC 10, at [170]. And see Sales, “Rights and Fundamental Rights”, making a similar argument (at 92–93), and arguing for an approach to identifying constitutional norms based in “tradition”.
57 Ibid., at 590–91. As commentators have observed, many of the cases asserting fundamental rights are “undoubtedly open to the charge that [their] authority is to be found in the pages of A Theory of Justice rather than in the pages of the Law Reports” (T. Hickman, “In Defence of the Legal Constitution” (2005) 55 U. Toronto L.J. 981, 984).
58 R. v Ministry of Defence, ex parte Smith [1996] Q.B. 517.
59 R. (Gillan) v Commissioner for the Metropolis [2006] UKHL 12, at [1], [15].
60 Elgizouli v Secretary of State for the Home Department [2020] UKSC 10, at [176]–[178], [198], [234].
61 R. (Privacy International) v Investigatory Powers Tribunal [2019] UKSC 22: cf. [43]–[44], [99] and [172], [182], [197]–[199].
62 Raymond v Honey [1983] A.C. 1, 13.
63 Pham v Secretary of State for the Home Department [2015] UKSC 19, at [119]; R. (Daly) v Secretary of State for the Home Department [2001] UKHL 26, [2001] 2 A.C. 532, at [15].
64 R. (Cherry) v Advocate General [2019] UKSC 41, at [48], and see [45], [50].
65 R. v Lord Chancellor, ex parte Witham [1998] Q.B. 575, 585.
66 R. (Cherry) v Advocate General [2019] UKSC 41, at [41]–[45], [50].
67 R. (Privacy International) v Investigatory Powers Tribunal [2019] UKSC 22; cf. [113]–[144] and [207]–[211].
68 Ibid.
69 R. (Anufrijeva) v Secretary of State for the Home Department [2003] UKHL 36, [2004] 1 A.C. 604, at [20].
70 Ibid., at [26], [28].
71 E.g. R. (Sandiford) v Secretary of State for Foreign and Commonwealth Affairs [2013] EWCA Civ 581, [2013] 1 W.L.R. 2938, at [61].
72 R. (Unison) v Lord Chancellor [2017] UKSC 51, at [66].
73 Elgizouli v Secretary of State for the Home Department [2020] UKSC 10, at [170], [193].
74 In this regard note Lord Sales's call for “caution”, “stability” and “slow waves of constitutional principle” (P. Sales, “Legalism in Constitutional Law: Judging in a Democracy” [2018] P.L. 687, 698).
75 For an illustrative example of different variants of the PoL being run together under the umbrella of the classic formulation, see Lady Hale, “Principle and Pragmatism in Public Law’, Sir David Williams Lecture 2019, Cambridge (18 October 2019), 12–15, available at https://www.supremecourt.uk/docs/speech-191018.pdf (last accessed 21 August 2020).
76 R. v Secretary of State for the Home Department, ex parte Pierson [1998] A.C. 539, 575. And see AXA v Lord Advocate [2011] UKSC 46, at [152].
77 Raymond v Honey [1983] A.C. 1.
78 Prison Act 1952, s. 47(1).
79 Raymond v Honey [1983] A.C. 1, 12–13, 15.
80 R. v Lord Chancellor, ex parte Witham [1998] Q.B. 575, 586; Raymond v Honey [1983] A.C. 1, 14F; R. (Daly) v Secretary of State for the Home Department [2001] UKHL 26, at [5]; cf. R. v Secretary of State for the Home Department, ex parte Leech [1994] Q.B. 198, 210–12. Lord Reed's judgment in Unison, considered below, supports the view that express words will be needed, at least in cases where statute purports completely to bar access to court: R. (Unison) v Lord Chancellor [2017] UKSC 51, e.g. at [76], [87].
81 R. (Cart) v Upper Tribunal [2011] UKSC 28, [2012] 1 A.C. 663, at [30].
82 Income Support (General) Regulations 1987, SI 1987/1967, reg. 70(3A).
83 R. (Anufrijeva) v Secretary of State for the Home Department [2003] UKHL 36, at [20].
84 Ibid., at [31].
85 Ibid., at [15].
86 Ibid., at [26], [28].
87 Varuhas, “Administrative Law and Rights’, 241–45, 250–54.
88 R. v Secretary of State for the Home Department, ex parte Leech [1994] Q.B. 198.
89 Ibid., at 209F–H, 217G.
90 Ibid., at 212F, 213B, 217G.
91 Ibid., at 218C.
92 Ibid., at 213–14.
93 Ibid., at 208B–C, 218C.
94 Ibid., at 217H–18A.
95 Campbell v U.K. (1992) 15 E.H.R.R. 137.
96 R. v Secretary of State for the Home Department, ex parte Leech [1994] Q.B. 198, 217B–F.
97 R. v Secretary of State for the Home Department, ex parte Simms [2000] 2 A.C. 115, 140A.
98 R. v Secretary of State for the Home Department, ex parte Leech [1994] Q.B. 198, 209D.
99 R. v Secretary of State for the Home Department, ex parte Simms [2000] 2 A.C. 115.
100 Ibid., at 125G.
101 Ibid., at 126–28, 131B–C, 132C.
102 Ibid., at 129D, 130A.
103 Ibid., at 127–29.
104 Ibid., at 130C.
105 Ibid., at 130C, G.
106 Ibid., at 126B–E, 131–32.
107 R. (Daly) v Secretary of State for the Home Department [2001] UKHL 26, at [5], emphasis added. And see [31].
108 Ibid., at [2].
109 Ibid., at [15], [17]–[18].
110 Ibid., at [21].
111 Ibid., at [23].
112 Although the augmented principle was not applied, there were, during this interregnum, a few instances where individual judges observed that the PoL may have a proportionality dimension: HM Treasury v Ahmed [2010] UKSC 5, [2010] 2 A.C. 534, at [122] (Lord Phillips); Pham v Secretary of State for the Home Department [2015] UKSC 19, at [113], [118]–[119] (Lord Reed).
113 R. (Unison) v Lord Chancellor [2017] UKSC 51.
114 Employment Tribunals and the Employment Appeal Tribunal Fees Order 2013, SI 2013/1893.
115 R. (Unison) v Lord Chancellor [2017] UKSC 51, at [87], and see [76]–[78], [90]–[98].
116 Ibid., at [88], and see [78]–[82], [99]–[102].
117 Ibid., at [78]–[79], [88]–[89].
118 Ibid., at [80], [88]–[89].
119 Ibid., at [80]–[82].
120 Ibid., at [80], [88]. And see R. (Cherry) v Advocate General [2019] UKSC 41, at [49].
121 Ibid., at [89].
122 Pham v Secretary of State for the Home Department [2015] UKSC 19, at [118]–[120].
123 R. (Unison) v Lord Chancellor [2017] UKSC 51, at [87]–[88], [98].
124 R. v Lord Chancellor, ex parte Witham [1998] Q.B. 575, 586.
125 Ibid., at 585–86 (and see R. (Unison) v Lord Chancellor [2017] UKSC 51, at [83]–[84]).
126 R. (Unison) v Lord Chancellor [2017] UKSC 51, at [90]–[98].
127 Ibid., at [90].
128 Ibid., at [91], [95].
129 Ibid., at [78]–[82], [88]–[89].
130 Ibid., at [86].
131 Ibid., at [99]–[102].
132 R. (Cherry) v Advocate General [2019] UKSC 41.
133 Ibid., at [49].
134 Ibid.
135 Ibid.
136 Ibid., at [50]–[51], [55]–[57].
137 Ibid., at [52].
138 Ibid., at [35]–[37], [52].
139 See e.g. ibid., at [51], [61].
140 Ibid., at [51], [58], [61].
141 Ibid., at [50], and see [58] (“extreme effect”).
142 Ibid., at [60].
143 Ibid.
144 Ibid., at [51].
145 Ibid., at [58].
146 Ghaidan v Godin-Mendoza [2004] UKHL 30, [2004] 2 A.C. 557.
147 HM Treasury v Ahmed [2010] UKSC 5, at [112]–[117].
148 Anisminic Ltd. v Foreign Compensation Commission [1969] 2 A.C. 147.
149 R. (Privacy International) v Investigatory Powers Tribunal [2019] UKSC 22, at [99]–[100].
150 Ibid., at [107].
152 See e.g. Burrows, Thinking About Statutes, 13–20; R. French, “The Principle of Legality and Legislative Intention” (2019) 40 Stat. L. Rev. 40; P. Sales, “Legislative Intention, Interpretation, and the Principle of Legality” (2019) 40 Stat. L. Rev. 53; J. Goldsworthy, “The Principle of Legality and Legislative Intention” in D. Meagher and M. Groves (eds.), The Principle of Legality in Australia and New Zealand (Sydney 2017); R. Ekins, The Nature of Legislative Intent (Oxford 2012).
153 Sales, “Legislative Intention”, 60. Even sceptics seemingly accept this benefit of parliamentary intention: Burrows, Thinking About Statutes, 18.
154 P. Sales, “In Defence of Legislative Intention” (2019) 48 Aust. Bar. Rev. 6, 17.
155 Freedom of Information Act 2000, ss. 1(1), 2; Pt II.
156 Freedom of Information Act 2000, s. 53.
157 R. (Evans) v Attorney General [2015] UKSC 21, at [52].
158 Ibid.
159 Ibid.
160 Ibid., at [56]–[58].
161 Ibid., at [115].
162 Ibid., at [78].
163 Ibid., at [71]–[78].
164 Ibid., at [115].
165 Ibid., at [123]–[131].
166 Ibid., at [153](i).
167 Ibid., at [168]–[169].
168 R. (Privacy International) v Investigatory Powers Tribunal [2019] UKSC 22, at [144].
169 R. v Secretary of State for the Home Department, ex parte Simms [2000] 2 A.C. 115, 131E–G.
170 E.g. R. (Morgan Grenfell & Co Ltd.) v Special Commissioner of Income Tax [2002] UKHL 21, [2003] 1 A.C. 563, at [44]; R. (Anufrijeva) v Secretary of State for the Home Department [2003] UKHL 36, at [27]; McE v Prison Service of Northern Ireland [2009] UKHL 15, [2009] 1 A.C. 908, at [62], [97], [100]; HM Treasury v Ahmed [2010] UKSC 5, at [61], [111], [193], [240]; AXA v Lord Advocate [2011] UKSC 46, at [151]; R. v Hughes [2013] UKSC 56, [2013] 1 W.L.R. 2461, at [27]; R. (Ingenious Media Holdings Plc) v Commissioners for HM Revenue and Customs [2016] UKSC 54, [2016] 1 W.L.R. 4164, at [19]; Welsh Ministers v PJ [2018] UKSC 66, [2019] 2 W.L.R. 82, at [24].
171 A notable exception is Ahmed, where Hansard was considered: HM Treasury v Ahmed [2010] UKSC 5, e.g. at [15]–[16], [152]–[154], [215], [222].
172 E.g. Hale, “Principle and Pragmatism in Public Law’, 12–15.
173 Lee v NSW Crime Commission [2013] HCA 39, (2013) 251 C.L.R. 196, at [314].
174 R. (Evans) v Attorney General [2015] UKSC 21, at [56]; R. (Privacy International) v Investigatory Powers Tribunal [2019] UKSC 22, at [100].
175 On this approach the PoL becomes a means for “inject[ing] normative content into legislative texts purely on the authority of the judges” rather than a check that the legislature has “sufficiently held in mind” basic norms: Sales, “Legislative Intention”, 62.
176 Text to notes 151–154 above.
177 See e.g. R. v Secretary of State for the Home Department, ex parte Simms [2000] 2 A.C. 115, 130B (conflation of anxious scrutiny Wednesbury and legality cases); H. Woolf, J. Jowell, C. Donnelly and I. Hare, De Smith's Judicial Review, 8th ed. (London 2019), ch. 11 (indiscriminate discussion of substantive review and legality cases in chapter on substantive review).
178 See e.g. Varuhas, “Administrative Law and Rights’, 245–54, 257–58, 267–77.
179 R. v Secretary of State for the Home Department, ex parte Brind [1991] 1 A.C. 696; R. v Ministry of Defence, ex parte Smith [1996] Q.B. 517.
180 Kennedy v Information Commissioner [2014] UKSC 20; Pham v Secretary of State for the Home Department [2015] UKSC 19.
181 Pham v Secretary of State for the Home Department [2015] UKSC 19, at [113]–[114], [118].
182 R. v Secretary of State for the Home Department, ex parte Brind [1991] 1 A.C. 696.
183 R. v Ministry of Defence, ex parte Smith [1996] Q.B. 517.
184 Pham v Secretary of State for the Home Department [2015] UKSC 19, at [114]–[117] (substantive review), [118]–[120] (legality).
185 Ibid., at [114]–[115].
186 AXA v Lord Advocate [2011] UKSC 46, at [135]–[154].
187 R. (Keyu) v Secretary of State for Foreign and Commonwealth Affairs [2015] UKSC 69, [2016] A.C. 1355.
188 Elgizouli v Secretary of State for the Home Department [2020] UKSC 10, at [176]–[178], [198], [234].
189 For a fuller discussion see Varuhas, “Administrative Law and Rights’, 263–78.
190 Ibid.
191 R. (Unison) v Lord Chancellor [2017] UKSC 51, at [3].
192 HRA, s. 7(1).
193 R. (Unison) v Lord Chancellor [2017] UKSC 51, at [89].
194 See e.g. R. (Daly) v Secretary of State for the Home Department [2001] UKHL 26, at [21].
195 R. (Unison) v Lord Chancellor [2017] UKSC 51, at [118]–[119].
196 R. (Cherry) v Advocate General [2019] UKSC 41, at [69].
197 AXA v Lord Advocate [2011] UKSC 46, at [143].
198 R. (Ingenious Media Holdings Plc) v Commissioners for HM Revenue and Customs [2016] UKSC 54, at [20].
199 R. v Lord Chancellor, ex parte Witham [1998] Q.B. 575, 586.
200 R. v Secretary of State for the Home Department, ex parte Leech [1994] Q.B. 198, 206–08.
201 Kruse v Johnson [1898] 2 Q.B. 91, 99–100.
202 Raymond v Honey [1983] A.C. 1, 4, 6 (Simon D. Brown and Andrew Collins for the appellant).
203 European Union (Withdrawal) Act 2018 (as amended by the European Union (Withdrawal Agreement) Act 2020).
204 R. v Lord Chancellor, ex parte Witham [1998] Q.B. 575, 579.
205 Prison Act 1952, s. 52(4) (previously Criminal Justice Act 1987, s. 66(4)).
206 R. v Lord Chancellor, ex parte Witham [1998] Q.B. 575, 579.
207 AXA v Lord Advocate [2011] UKSC 46, at [42]–[52], [135]–[148], [177].
208 Ibid., at [149]–[153].
209 R. (Cherry) v Advocate General [2019] UKSC 41, at [35]–[37], [52]–[54].
210 R. (DSD) v Parole Board [2018] EWHC 694 (Admin), [2019] Q.B. 285, at [190], emphasis added.
211 Lady Hale, “Principle and Pragmatism in Public Law’, 15.
212 R. (Cherry) v Advocate General [2019] UKSC 41, at [51], [58].
213 R. v Secretary of State for the Home Department, ex parte Pierson [1998] A.C. 539, 575–76.
214 See e.g. Varuhas, J.N.E., “Against Unification” in Wilberg, H. and Elliott, M. (eds.), The Scope and Intensity of Substantive Review (Oxford 2015)Google Scholar; J.N.E. Varuhas, “Taxonomy and Public Law” in Elliott, Varuhas and Stark (eds.), The Unity of Public Law?, 71–78.