Module Name : Constitutional Law
QUESTION
In his coverage of separation of powers, King stated that it is an important part of the UK
constitution, “…. the idea being that various organs ……. should be separated from one another and
be charged with acting as a check on one another.”
- Anthony King, The British Constitution (Oxford University Press 2007) 356
IS THE SEPARATION OF POWERS IN THE UK EFFECTIVE?
“Power tends to corrupt, and absolute power corrupts absolutely.”1
Lord Acton’s well-known notion was echoed in Montesquieu’s elucidation of separation of powers; a
doctrine that requires the complete demarcation between the three constitutional functions and the
institutions exercising those functions —the legislature, executive and judiciary.2 Lord Templeman
succinctly summarized these functions as: “Parliament makes the law, the executive carry the law in
effect and the judiciary enforce the law.”3 At the heart of this doctrine are two underlying rationales:
liberty and efficiency. Montesquieu4 and Barendt endorse the former, arguing that that the doctrine
prevents abuse of power that interferences with citizens’ rights by distributing that power amongst the
three branches, while Barber takes the alternate view and states that the purpose is efficient
governance, which is achieved by allocating powers to the institutions best able to make use of them.5
Locke, on the other hand, suggests that the two motivations are compatible: an efficient constitution
promotes and fosters liberty. 6
Adherence to separation is reflected in several constitutions like that of the US, but as Professor
Bradley has noted, “the interaction of the judiciary, executive and legislature is a fundamental
aspect”7 of a complex modern democratic state like that of the UK, and thus, a pure separation has
never been a feature of its constitution. 8 Instead, the UK adopts a partial model, recognizing the broader
1
Anne Dennett, Public Law Directions (OUP 2019) Ch 6.
2
John Stanton and Craig Prescott, Public Law (11th edn, OUP 2020) Ch 2.
3
M v Home Office [1994] 1 AC 377, 395.
4
Charles Montesquieu, The Spirit of the Laws (1750) Book XL s6.
5
Nicholas W Barber, ‘Prelude to the Separation of Powers’ (2001) 60(1) CLJ 59.
6
Ibid.
7
House of Lords Select Committee on the Constitution, ‘Relations between the Executive, the Judiciary and
Parliament’, 6th Report of Session 2006–07, HL Paper 151, p 69 (2).
8
Neil Parpworth, Constitutional and Administrative Law (11th edn, OUP 2020) Ch 2.
, benefit of allowing a degree of overlap so that, in compliance with King’s statement, “each branch...is
able to check the exercise of power by the other. 9” This essay will examine the relationships and
sophisticated interplays between the three organs to argue that partial separation more effectively
captures the objectives of liberty and efficiency, particularly in light of recent reform and the
emergence of courts as a more prominent advocate for separation of powers.
THE LEGISLATURE AND JUDICIARY
At first glance, the relationship seems clear; Parliament makes the law and the primary judicial function
is to interpret and apply the law so as to give effect to the will of Parliament. 10 However, this
relationship is defined by the doctrine of parliamentary sovereignty which, according to the Diceyan
conception, casts Parliament as the supreme legislative force and allows Parliament to enact, amend or
repeal any law while also asserting that no subordinate constitutional body, including the courts, may
question its authority.11 Consequently, Dicey’s exposition seems to contradict Montesquieu’s design
of constitutional functions that are separate yet equal in power.
This is better understood by recognizing the significance of judicial precedent and the courts’
legislative function when developing the common law and interpreting statutes. Statutes do not seek
to provide for every scenario explicitly and necessarily leave room for judicial interpretation12, as
illustrated by Laws, “An Act of Parliament is words of a page. Only the common law gives it life. 13”
R v R14 is a case often cited as an example of interstitial law-making where judges ‘filled in the gaps’
of an area not provided for by statutes. Consequently, parliamentary sovereignty is necessary is to
determine which of the two law-making institutions is to prevail if they create conflicting laws 15; it
only makes sense that the democratically representative Parliament emerges over a body of unelected
judges.
9
Eric Barendt, An Introduction to Constitutional Law (OUP 1998) 15.
10
Stanton and Prescott (n 2).
11
AV Dicey, Introduction to the Study of the Law of the Constitution (1885).
12
Judith Embley and others, Legal Systems & Skills: Learn, Develop, Apply (4th edn, OUP 2020) 159-160.
13
John Laws, ‘The Common Law Constitution, Hamlyn Lectures 2013’ The Common Law Constitution (Cambridge
University Press 2014).
14
R v R [1991] 4 All ER 481.
15
Richard White, ‘Separation of Powers and Legislative Supremacy’ (2011) 127 LQR 456.