Separation of Powers in Irish Constitutional Law

The tripartite division of power (Article 6)

Article 6 declares that all powers of government — legislative, executive and judicial — derive from the people and are exercised only by the organs the Constitution establishes. This tripartite division is the backbone of the subject and generates a steady stream of problems asking whether one organ has strayed into another's territory.

The recurring skill is characterisation: name the power, identify which organ is acting, and ask whether it has crossed a constitutional line. Each power has its own boundary — the non-delegation doctrine for the legislature, the limits on the executive residue, and the reservation of the administration of justice to the courts.

Legislative power and delegation (Article 15)

Article 15.2.1° vests the sole and exclusive power of making laws in the Oireachtas, so the Oireachtas may not delegate its law-making power. It may, however, authorise a Minister or body to fill in the details of a policy the Oireachtas has itself set, and Article 15.2.2° expressly permits the creation of subordinate legislatures.

The dividing line is the principles-and-policies test. Not every ministerial power is law-making: a power to make an individual decision or run an administrative arrangement is executive or administrative rather than legislative — as in Casey v Minister for Arts, Heritage, Gaeltacht and the Islands [2004] IESC 14; [2004] 1 IR 402 IE · Supreme Court, on the scheme limiting access to Skellig Michael. In Sivsivadze v Minister for Justice [2015] IESC 53 IE · Supreme Court the Court rejected an Article 15 challenge to the power to make a deportation order under s.3 of the Immigration Act 1999, Murray J holding that the section does not conflict with Article 15 and following TC v Minister for Justice [2005] 4 IR 109.

EU law is a special case: Section 3 of the European Communities Act 1972 permits implementation by statutory instrument, and Article 29.4.6° gives constitutional immunity to measures necessitated by EU membership (Meagher v Minister for Agriculture and Food [1994] 1 IR 329 IE · Supreme Court; Maher v Minister for Agriculture [2001] IESC 32; [2001] 2 IR 139 IE · Supreme Court). “Necessitated” is a threshold, not a blanket — where a measure goes further than membership requires, the immunity does not apply, so the point has to be argued rather than assumed.

The principles-and-policies test

In Cityview Press v An Chomhairle Oiliúna (ANCO) [1980] IR 381 IE · Supreme Court, the Supreme Court framed the test as whether the challenged measure is more than a mere giving effect to principles and policies which are contained in the statute. If the law is laid down in the Act and the delegate only fills in details, the delegation is valid; if the delegate is left to choose the policy, it is an unconstitutional exercise of legislative power.

Cityview laid the test down in the Supreme Court. It was elaborated in the High Court in John Grace Fried Chicken Ltd v Catering Joint Labour Committee [2011] IEHC 277 IE · High Court (Feeney J), which treats it as flexible: the court reads the whole statute, gives due regard to technical or complex subject-matter, and identifies the statutory purpose as the backdrop. Levies in Cityview were valid; a power to impose or vary duty with no guiding policy in McDaid v Sheehy IE · Supreme Court was invalid; the deportation power in Laurentiu v Minister for Justice [1999] IESC 47; [1999] 4 IR 26 IE · Supreme Court was invalid for lacking any principles; and sector-wide Registered Employment Agreements in McGowan v The Labour Court [2013] IESC 21; [2013] 3 IR 718 IE · Supreme Court were a wholesale abdication.

Bederev v Ireland ran to three judgments and the middle one went the other way, so name the level you mean. The High Court dismissed the challenge; the Court of Appeal [2015] IECA 38 IE · Court of Appeal held the power bad; and the Supreme Court [2016] IESC 34; [2016] 3 IR 1 IE · Supreme Court reversed and upheld the power to schedule controlled drugs, the principles being implied — found in the long title and by reading s.2(2) of the Misuse of Drugs Act 1977 as limited by the categories already in the Schedule. A bare “Bederev” can send a reader to the judgment that decided the opposite way.

In DPP v District Judge McGrath [2021] 2 ILRM 345 the Court cautioned that the test is helpful but not an infallible guide.

The Supreme Court has since reframed the question, and this is where the modern law sits. The law on Article 15.2.1° was restated in Náisiúnta Leictreach Contraitheoir Éireann v The Labour Court [2021] IESC 36 IE · Supreme Court, and in Conway v An Bord Pleanála [2024] IESC 34 IE · Supreme Court and Gearty v DPP [2024] IESC 45 IE · Supreme Court the Supreme Court took it past the standard Cityview formulation. Conway records the parties accepting that the law “had moved on from the standard ‘principles and policies’ test”, and the modern question is whether the body given the power has abdicated its function, judged on all the circumstances, with principles and policies one consideration among several rather than a self-contained test. Start a delegation problem at Cityview, but finish it here.

Executive power (Article 28)

Article 28.2 does not vest the executive power. It provides that the executive power of the State shall, subject to the provisions of the Constitution, be exercised by or on the authority of the Government. The contrast with Article 15.2.1°, where law-making is vested in the Oireachtas, is worth holding on to: it is the “or on the authority of” limb that covers a Minister acting on a Government decision. The Constitution does not define the power. The much-cited description — the executive power is the residue left when the judicial and legislative powers are subtracted — is Professor Casey's, adopted by O'Donnell J in Barlow v Minister for Agriculture [2016] IESC 62; [2017] 2 IR 440 IE · Supreme Court. Beyond explicit powers (defence, the budget, international agreements), the Government holds implicit powers normally exercised by a sovereign State, and a non-statutory inquiry is set up under that executive power. Shatter v Guerin [2019] IESC 9 IE · Supreme Court is the authority on how such an inquiry may report: where its findings affect a person's reputation, fair procedures apply.

The key limit is that the executive cannot override or suspend the law. In NVH v Minister for Justice [2017] IESC 35 IE · Supreme Court the Court confirmed that executive power does not extend to repealing or overriding legislation, and in Burke v Minister for Education and Skills [2022] IESC 1 IE · Supreme Court the Court described executive power as broad but reviewable, with a clear disregard threshold for non-rights matters and a reasonableness standard for rights-based challenges. Burke also has a Court of Appeal judgment, [2021] IECA 67 IE · Court of Appeal, so name the level you mean.

Judicial power and the administration of justice (Article 34)

Under Article 34.1, justice is administered in courts established by law, by judges, and — save in such special and limited cases as may be prescribed by law — in public. That express exception is what lets statute provide for a hearing in camera. The administration of justice is reserved to the courts, while Article 37.1 allows limited functions and powers of a judicial nature to be exercised in non-criminal matters by a person or body duly authorised by law to exercise them.

What counts as administering justice is set by McDonald v Bord na gCon (No. 2) [1965] IR 217 IE · Supreme Court: the five characteristics were given in the High Court and approved by the Supreme Court on appeal — a dispute about legal rights, a determination of them, a final determination, an order capable of enforcement, and an order of a kind historically made by the courts. Cite (No. 2) — the earlier report, McDonald v Bord na gCon & AG [1964] IR 350, is a different decision on a preliminary issue and says nothing about the five characteristics.

The test has since been loosened. In Keady v Commissioner of An Garda Síochána [1992] 2 IR 197 IE · Supreme Court the Court distilled the characteristics to two essential ingredients — a contest between parties together with the infliction of some form of liability or penalty — and, finding no contest on the facts, held Garda disciplinary proceedings were not the administration of justice. In Zalewski v An Adjudication Officer & WRC [2021] IESC 24 IE · Supreme Court the Court held the five limbs are not a rigid checklist and that the WRC administers justice in a form permissibly limited under Article 37.

One organ may not usurp another's function

The judicial power is protected by a ban on interference with the judicial function: the Oireachtas may change the law but may not direct the outcome of, or interfere with, proceedings already before the courts. In Buckley v Attorney General an Act directing the disposal of funds in litigation already before the courts was an unwarrantable interference; in Maher v Attorney General [1973] IR 140 IE · Supreme Court making a certificate conclusive evidence usurped the court's fact-finding role. By contrast, a merely rebuttable presumption was upheld in McGonnell v Attorney General [2006] IESC 64 IE · Supreme Court.

Sentencing is also exclusively judicial: Deaton v Attorney General [1963] IR 170 IE · Supreme Court holds that the choice of penalty in an individual case cannot be handed to the executive, and Ellis v Minister for Justice [2019] IESC 30 IE · Supreme Court struck down a mandatory minimum triggered by a previous conviction.

The courts, in turn, will not do the political branches' work. O'Reilly v Limerick Corporation [1989] ILRM 181 IE · High Court distinguishes commutative justice (within the courts' remit) from distributive justice (allocating public resources — for the political branches), and the Supreme Court adopted that distinction in TD v Minister for Education [2001] IESC 101; [2001] 4 IR 259 IE · Supreme Court, holding that a mandatory injunction compelling the State to build facilities breached the separation of powers. Out of the same respect, the courts generally will not review the internal workings of the Oireachtas (O'Malley v An Ceann Comhairle IE · Supreme Court), though a statutory procedure may be reviewable (Callely v Moylan [2014] 4 IR 112 IE · Supreme Court, on appeal from [2011] IEHC 2 IE · High Court).

Key authorities

The leading authorities relied on in the source module (a fuller case table is in the paid module):

• Cityview Press v An Chomhairle Oiliúna (ANCO) [1980] IR 381 IE · Supreme Court — Delegation valid only where the Act supplies the principles and policies.
• Laurentiu v Minister for Justice [1999] IESC 47; [1999] 4 IR 26 IE · Supreme Court — Deportation power lacking any principles or policies was invalid delegation.
• McGowan v The Labour Court [2013] IESC 21; [2013] 3 IR 718 IE · Supreme Court — Sector-wide binding agreements were a wholesale abdication of law-making power.
• Barlow v Minister for Agriculture [2016] IESC 62; [2017] 2 IR 440 IE · Supreme Court — Executive power is the residue left after legislative and judicial power.
• NVH v Minister for Justice [2017] IESC 35 IE · Supreme Court — Executive power cannot repeal or override legislation.
• McDonald v Bord na gCon (No. 2) [1965] IR 217 IE · Supreme Court — Five limbs defining the administration of justice reserved to the courts.
• Zalewski v An Adjudication Officer & WRC [2021] IESC 24 IE · Supreme Court — Five-limb test is indicative, not a rigid checklist; Article 37 limited functions.
• Buckley v Attorney General [1950] IR 67 — Directing disposal of funds in existing proceedings was interference with the courts.
• Deaton v Attorney General [1963] IR 170 IE · Supreme Court — Choice of penalty is judicial and cannot be given to the executive.
• TD v Minister for Education [2001] IESC 101; [2001] 4 IR 259 IE · Supreme Court — Mandatory order compelling resource allocation breached separation of powers.
• Callely v Moylan [2014] 4 IR 112 IE · Supreme Court — A statutory disciplinary procedure over an Oireachtas member is justiciable.

Key statutory references: Article 6; Article 15.2.1° and 15.2.2°; Article 28.2; Article 29.4.6°; Article 34.1 and Article 37.1; European Communities Act 1972, s. 3.

Exam focus: how to identify a separation-of-powers issue

1. Identify which organ is acting — a Minister or body making rules, the Government, a body deciding disputes, or a court asked to review the Oireachtas.
2. For rule-making, ask whether the power is truly legislative or merely an individual/administrative decision outside Article 15.2.1° (Casey; Sivsivadze).
3. If legislative, start at Cityview and read the whole Act (John Grace) for principles and policies — detail-filling is valid, policy-choosing is invalid — then put the modern question from Conway and Gearty: has the body given the power abdicated its function, on all the circumstances?
4. For EU-implementing measures, use the 'necessitated' question under s.3 of the European Communities Act 1972 and Article 29.4.6° rather than Cityview.
5. For a decision-making body, run the McDonald (No. 2) limbs as loosened by Zalewski and Keady, then ask whether it is a 'limited', non-criminal function saved by Article 37.
6. Check for one organ usurping another: legislative interference with existing cases (Buckley; Maher), removal of sentencing (Deaton; Ellis), or courts asked to allocate resources (O'Reilly; TD).
7. State a clear conclusion on which side of the line the measure falls, noting the caution in McGrath about boilerplate 'principles and policies'.

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