An Introduction to the Duty of Candour

Defining the Duty of Candour

The duty of candour requires parties to judicial review applications, especially government respondents, to “to make full and fair disclosure”.[1] They must “explain fully what has occurred and why”.[2] The duty has been recognized by the English courts[3] and by courts in other jurisdictions, such as New Zealand,[4] Ireland[5] and Northern Ireland,[6] whilst in Australia government respondents are subject to duties of “model litigants”.[7]

Content of the Duty of Candour

Under the duty of candour, a duty is owed to the court “to cooperate and to make candid disclosure, by way of affidavit, of the relevant facts and (so far as they are not apparent from contemporaneous documents which have been disclosed) the reasoning behind the decision challenged in the judicial review proceedings”.[8] The duty lies more heavily on the government, as that is where relevant information is most likely to be held, but it is also owed by applicants.[9] To discharge the duty the parties must act with “frankness and openness”[10] by providing “a true and comprehensive account of the way the relevant decisions in the case were arrived at”,[11] “based on a rigorous analysis of the evidence”.[12] This extends to providing an explanation in comprehensible terms of dense technical or scientific material.[13]

Relevance is the touchstone; litigation advantage is irrelevant. “Embarrassing” or “damaging” material must be disclosed, as must “inconvenient” facts or relevant considerations:[14] the respondent must identify “the good, the bad and the ugly”.[15] In short, the respondent must place “all the cards face upwards on the table”.[16]

These cards must be arrayed in a comprehensible way, not in an “undigested pile”.[17] The duty of candour is owed to the courts, to ensure that they can perform their reviewing function.[18] Accordingly, it is not a duty to disclose large amounts of documentation – to off-load a huge amount of documentation on the claimant and ask it, as it were, to find the “needle in the haystack”[19] – but rather a duty to throw as much light as possible on the relevant facts. In public law litigation, the government may not adopt a “win a case at all costs” mentality,[20] because the respondent and the courts are engaged in the “common enterprise” of fulfilling “the public interest in upholding the rule of law”.[21] The duty applies with greater force in situations where fundamental rights are at stake;[22] in such circumstances, it is “even more acute”.[23]

It has been said that the duty of candour is the “constitutional corollary” of deference to the executive: in return for deference, the Courts expect “Ministerial candour with the Courts about their policy”.[24] Accordingly, it applies “with greatest force at the outset of the proceedings”.[25]

The Basis of the Duty of Candour

The duty of candour is rooted, fundamentally, in the proposition that the government should abide by the law.

Courts around the common law world have long recognized that in order to perform their reviewing function, they must be “as fully informed as reasonably possible of the facts and issues as they presented themselves at the time to the authority whose decision is under review”.[26]   Accordingly, it has been said that the duty of candour is “essential for the maintenance of the rule of law”, as discharging the duty is necessary to permit the courts to ensure that the government has complied with the law.[27] As such, the duty is premised on the existence of a collaborative relationship between the government and the courts, a “partnership based on a common aim, namely the maintenance of the highest standards of public administration”.[28] It is “the duty of the executive to assist the court in arriving at the proper and just result”.[29] Indeed, this duty can be grounded in deeper soil still, the “standard of fair play to be observed by the Crown in dealing with subjects”,[30] or the Crown’s status as “the source and fountain of justice”,[31] through the Attorney General.[32] It reflects the Crown’s long-standing commitment to the accurate resolution of disputes between citizens and the state.


[1] R v Lancashire County Council ex p. Huddleston [1986] 2 All ER 941, at p. 945 per Sir John Donaldson MR.

[2] R v Lancashire County Council ex p. Huddleston [1986] 2 All ER 941, at p. 945 per Sir John Donaldson MR.

[3] R v Lancashire County Council ex p. Huddleston [1986] 2 All ER 941, at p. 945 per Sir John Donaldson MR.

[4] Ririnui v Landcorp Farming Ltd [2016] NZSC 62, [2016] 1 NZLR 1056, at para. 105, per Elias CJ and Arnold J.

[5] O’Neill v. Governor of Castlerea Prison [2004] 1 IR 298, at p. 316; Murtagh v. Kilrane [2017] IEHC 384 (though note that the ordinary civil procedure principles of discovery apply to judicial review proceedings in Ireland: Hogan, Morgan and Daly, Administrative Law in Ireland, 5th ed. (Dublin, 2019), at para. 18-81). See also RAS Medical Limited trading as Parkwest Clinic v. Royal College of Surgeons in Ireland [2019] IESC 4, at para. 6.9, per Clarke CJ.

[6] See e.g. Re Downes [2006] NIQB 77, at para. 31; Bryson v Police Service Of Northern Ireland [2019] NIQB 51, at para. 46.

[7] Janina Boughey, “Litigation by and Against Government” in Weeks et al, Governmental Liability: Principles and Remedies (Canberra, 2019).

[8] Belize Alliance of Conservation Non-Governmental Organizations v The Department of the Environment [2004] UKPC 6, [2004] Env LR 761, at para [86], per Lord Walker (dissenting, but not on this point).

[9] R (Khan) v Secretary of State for the Home Department [2016] EWCA Civ 416, at para. 46, per Beatson LJ. See also Hogan, Morgan and Daly, Administrative Law in Ireland, 5th ed. (Dublin, 2019), at para. 18-149 to para. 18-155.

[10] Re Downes [2006] NIQB 77, at para. 31, per Girvan J.

[11] R (Quark Fishing Ltd) v Secretary of State for Foreign and Commonwealth Affairs [2002] EWCA Civ 1409, [2002] All ER (D) 450 (Oct), at para [50], per Laws LJ. See also R (Khan) v Secretary of State for the Home Department [2016] EWCA Civ 416, at para. 46, per Beatson LJ (in relation to a claimant’s failure of candour).

[12] Treasury Solicitor’s Department, Guidance on Discharging the Duty of Candour and Disclosure in Judicial Review Proceedings (January 2010), pp. 2-3.

[13] R (Mott) v Environment Agency [2016] EWCA Civ 564, [2016] 1 WLR 4338, at para. 64, per Beatson LJ.

[14] Treasury Solicitor’s Department, Guidance on Discharging the Duty of Candour and Disclosure in Judicial Review Proceedings (January 2010), pp. 2-3.

[15] R (Hoareau) v Secretary of State for Foreign and Commonwealth Affairs [2018] EWHC (Admin) 1508, at para. 20, per Singh LJ

[16] R v Lancashire County Council ex p. Huddleston [1986] 2 All ER 941, at p. 945 per Sir John Donaldson MR.

[17] R (Khan) v Secretary of State for the Home Department [2016] EWCA Civ 416, at para. 46, per Beatson LJ.

[18] R (Hoareau) v Secretary of State for Foreign and Commonwealth Affairs [2018] EWHC (Admin) 1508, at paras. 19-20, per Singh LJ.

[19] R (Hoareau) v Secretary of State for Foreign and Commonwealth Affairs [2018] EWHC (Admin) 1508, at para. 20, per Singh LJ

[20] Abraha v Secretary of State for the Home Department [2015] EWHC 1980 (Admin) at para. 111, per Singh J (as he then was)

[21] R (Hoareau) v Secretary of State for Foreign and Commonwealth Affairs [2018] EWHC (Admin) 1508, at paras. 19-20, per Singh LJ.

[22] I v Secretary of State for the Home Department [2010] EWCA Civ 727, at para. 54, per Munby LJ.

[23] R (Al-Sweady) v Secretary of State for Defence [2009] EWHC (Admin) 2387, at paras. 25-26, per Scott Baker J. R (K) v London Borough of Brent [2018] EWHC (Admin) 1068, at para. 11, per David Elvin QC.

[24] New Zealand Fishing Industry Association Inc v Minister of Agriculture and Fisheries [1988] NZCA 198, [1988] 1 NZLR 544, at p. 554 per Cooke P (as he then was).

[25] Bryson v Police Service Of Northern Ireland [2019] NIQB 51, at para. 40.

[26] Fiordland Venison Ltd v. Minister of Agriculture and Fisheries [1978] 2 N.Z.L.R. 341, at p. 346, per Cooke P (as he then was).

[27] Abraha v Secretary of State for the Home Department [2015] EWHC 1980 (Admin) at [111] and [114], per Singh J (as he then was).

[28] R v Lancashire County Council ex p. Huddleston [1986] 2 All ER 941, at p. 945 per Sir John Donaldson MR.

[29] P & C Cantarella v Egg Marketing Board (NSW) [1973] 2 NSWLR 368 at 383, per Mahoney J, cited in Boughey.

[30] Melbourne Steamship Co Ltd v Moorehead (1912) 8 CLR 330, at p. 342, per Griffith CJ.

[31] Sebel Products v Commissioner of Customs and Excise [1949] Ch 409, at p. 413, per Vaisey J, cited by Gabrielle Appleby, “The Government as Litigant” (2014) 37(1) University of New South Wales Law Journal 94.

[32] See also Dyson v Attorney-General [1911] 1 KB 410, at pp. 421-422; and Deare v Attorney General (1835) 1 Y & C Ex 196, at p. 208: “it has been the practice, which I hope never will be discontinued, for the officers of the Crown to throw no difficulty in the way of any proceeding for the purpose of bringing matters before a Court of justice, where any real point of difficulty that requires judicial decision has occurred”.

This content has been updated on January 5, 2023 at 17:30.