Case Note

• Author: CHEN Siyuan LLB (Hons) (National University of Singapore); Justices‘ Law Clerk & Assistant Registrar, Supreme Court of Singapore.
• Published date: 01 December 2011
• Date: 01 December 2011

THE RELATIONSHIP BETWEEN INTERNATIONAL LAW AND DOMESTIC LAW

Yong Vui Kong v PP

[2010] 3 SLR 489

The Court of Appeal in Yong Vui Kong v PP [2010] 3 SLR 489 recently addressed at length the issue of the constitutionality of the mandatory death penalty. In the main, the appellant had argued that the mandatory death penalty was unconstitutional because it violated Art 9(1) of the Constitution of the Republic of Singapore (1999 Rev Ed), which states that: “No person shall be deprived of his life or personal liberty save in accordance with law.” The court ultimately rejected this argument. This piece focuses on the main international law issue emanating from the said constitutional challenge, viz, the relationship between international law and domestic law.

I. Establishing the context

1 The appellant in Yong Vui Kong v PP1 (“Yong Vui Kong”) was 19 years old when he attempted to traffic drugs from Malaysia to Singapore. Subsequent to his arrest, he was convicted under the Misuse of Drugs Act2 for trafficking in 47.27g of diamorphine,3 a controlled drug, and was sentenced to death.4 He challenged his sentence on various grounds, but failed in the end. The resulting judgment by the Court of Appeal was very rich, dealing with various aspects of constitutional law, international law, criminal law and legal theory. This note will deal only with the international law issues that emanate from the constitutional arguments made by the appellant, viz, the relationship between international law and domestic law.

2 It should be said that this was not the first time that the mandatory death penalty in Singapore had been challenged on constitutional grounds: previous (and similarly unsuccessful) challenges include the Privy Council decision in Ong Ah Chuan v PP5 and the Court of Appeal decision in Nguyen Tuong Van v PP.6 Incidentally, these two cases were considered in detail by the Court of Appeal in Yong Vui Kong.7 And just as in those two cases, the appellant in Yong Vui Kong rested his main constitutional argument on Art 9(1) of the Constitution of the Republic of Singapore (“Constitution”).8

3 Article 9(1) of the Constitution states that:9“No person shall be deprived of his life or personal liberty save in accordance with law.” The expression “law” is defined in Art 2 of the Constitution as including “written law and any legislation of the United Kingdom or other enactment or instrument whatsoever which is in operation in Singapore and the common law in so far as it is in operation in Singapore and any custom or usage having the force of law in Singapore”. Article 2(1) also states that “written law” refers to “this Constitution and all Acts and Ordinances and subsidiary legislation for the time being in force in Singapore”.

4 The appellant‘s argument on Art 9(1) of the Constitution10 that is relevant for present purposes was that any mandatory death penalty legislation was not “law” for the purposes of Art 9(1), because “law” included international law - and according to the appellant, customary international law prohibited the mandatory death penalty because it was a form of “inhuman punishment”.11

II. The decision by the Court of Appeal

5 In relation to the aforementioned argument, the Court of Appeal made the following observations:

(a) While the appellant asserted that customary international law was part of the expression “law” in Art 9(1) of the Constitution,12 the appellant cited no authorities for this.13 In response, the Prosecution accepted that “in principle, the expression ‘law‘ should be interpreted to include [customary international law]”.14 The Court of Appeal, however, resisted this and noted the wider ramifications if it was true that “law” in Art 9(1) included customary international law: “We do not think that the AG, by this reply, was conceding that the expression ‘law‘ in Art 9(1) includes CIL in the sense that ‘law‘ has been defined to include CIL, with the consequence that, once it is shown that there is a rule of CIL prohibiting the MDP as an inhuman punishment, that CIL rule automatically becomes part of ‘law‘ for the purposes of Art 9(1). Indeed, the constitutional definition of ‘law‘ in Art 2(1) is quite different … Besides, such a concession would be contrary to the decision in Nguyen, where this court held at [94], citing (inter alia) the Privy Council case of Chung Chi Cheung v The King [1939] AC 160… that in the event of a conflict between a rule of CIL and a domestic statute, the latter would prevail. From his other submissions, it seems clear enough to us that what the AG meant when he said that the expression ‘law‘ should be interpreted to include CIL was that this expression would include a CIL rule which had already been recognised and applied by a domestic court as part of Singapore law”.15

(b) Domestic law, including the Constitution, should, “as far as possible, be interpreted consistently with Singapore‘s international legal obligations. There are, however, inherent limits on the extent to which our courts may refer to international human rights for this purpose. For instance, reference to international human rights norms would not be appropriate where the express wording of the Singapore Constitution is not amenable to the incorporation of those international norms … for our courts to give effect to [such

norms], it would be necessary Parliament to first enact new laws (as the drafters of the [Universal Declaration of Human Rights] hoped States would do) or even amend the Singapore Constitution to expressly provide for rights which have not already been incorporated therein”.16

(c) It was not possible to incorporate a prohibition against inhuman punishment through the interpretation of Art 9(1) of the Constitution because: (i) the Constitution does not contain any express prohibition against inhuman punishment;17 (ii) the European Convention of Human Rights18 (“ECHR”) (which certain Commonwealth states subsequently modelled their constitutions after) had ceased to apply in British colonies upon their independence;19 (iii) when the 1957 Malayan Constitution (which heavily influenced the part on fundamental liberties in our Constitution) was drafted, no reference or recommendation was made vis-…-vis a prohibition against inhuman punishment even though the Reid Commission knew of the ECHR;20 (iv) there was again an omission of the prohibition against inhuman punishment from the 1963 Malaysian Constitution (a later version of the 1957 Malayan Constitution, which also heavily influenced the part on fundamental liberties in our Constitution);21 and (v) a proposal by the Wee Chong Jin Commission in 1966 to add an express constitutional provision (Art 13) prohibiting torture or inhuman punishment was unambiguously rejected by the Government.22 The proposed Art 13 was the same as Art 3 of the ECHR.23

(d) States are “not bound to give effect in their Constitutions to norms and standards elsewhere”,24 and if “the requisite legislative support for a change in the Constitution is forthcoming, a deliberate departure from fundamental human rights may be made, profoundly regrettable although this may be. That is the prerogative of the legislature”.25 There is, “in substance, no difference between repealing an existing constitutional provision prohibiting inhuman punishment and

deliberately deciding not to enact such a constitutional provision in the first place” [emphasis in original].26

(e) Once a customary international norm has been incorporated by the domestic courts into the domestic laws, it becomes part of the common law. The common law, however, is subordinate to statute law. If the expression “law” in Art 9(1) of the Constitution includes customary international law, “the hierarchy of legal rules would be reversed: any rule of [customary international law] that is received via the common law would be cloaked with constitutional status and would nullify any statute or any binding judicial precedent which is inconsistent with it”.27

(f) A rule of customary international law is not selfexecuting;

“it cannot become part of domestic law until and unless it has been applied as or definitively declared to be part of domestic law by a domestic court. The expression ‘law‘ is defined in Art 2(1) to include the common law only ‘in so far as it is in operation in Singapore‘… given the existence of the [mandatory death penalty] in several of our statutes, our courts cannot treat the alleged [customary international law] rule prohibiting inhuman punishment as having been incorporated into Singapore law”.28

(g) If there is a conflict between a rule of customary international law and a domestic statute, the latter prevails.29

III. Some comments on the decision

6 As alluded to earlier, it is impossible within the confines of this note to review every aspect of the judgment, so this note will only focus on the international law issues that emanate from the constitutional arguments made by the appellant. While it is submitted that the Court of Appeal‘s decision in Yong Vui Kong30 in this regard is generally sound and uncontroversial, the decision could have benefitted from a more complete discourse by bringing in and discussing various orthodox strands of thought in contemporary international law.

A. Whether “law” includes customary international law - Monist and dualist approaches

7 A local commentator once pointed out: “While [the Constitution] is silent in key respects on the interaction between international law and the Singapore domestic legal system, the executive, legislative and judicial branches in Singapore have all demonstrated a keen appreciation of what international law requires and allows.”31 Indeed, in the aftermath of Nguyen Tuong Van v PP,32 it was commented that if the expression “law” in Art 9(1) of the Constitution33 included rules of customary international law, this would make “the Singapore Constitution a closer cousin of the American...