Constitutional Institutions Lecture

The Separation of Powers

Public law regulates the relationship between the state and its organs, and private citizens. Public law is a shorter way of describing constitutional and administrative law. Constitutional law is the law that provides a state framework and establishes its principle institutions and the interrelationships between these institutions. Administrative law governs the exercise of the legal powers and legal duties of public bodies and authorities.

The separation of powers serves an essential democratic function, since it enables the three main powers of the state to act as a check on the absolute exercise of power. These powers are divided between three principle branches of government. Firstly, the legislative branch has powers to create legislation and to represent the views of the people. Second, the judicial branch is the systems of courts and tribunals who have powers to interpret legislation passed by the legislature and to adjudicate on legal disputes. Thirdly, the executive branch has the responsibility of making and implementing public policy.

Throughout history, many constitutional writers have regarded the separation of powers principle as representing the ideal structure of government. Charles Louis de Secondat, otherwise known as Baron de Montesquieu wrote about his observations whilst travelling around Europe between 1728 and 1731. He is one of the writers who is most closely associated with this doctrine. In The Spirit of Laws, Montesquieu warned against the use of power in a 'tyrannical manner' if it was not divided between the three branches of government. Much of his observations were carried out within the court of George II in England, moving in political circles and formulating much of his work based on the English government of the time.

Modern democracies tend to now exist as a partial, or 'checks and balances', conception of the separation of powers, which includes the ability of one branch to involve itself in issues that are primarily the concern of another branch. Constructive breaches of the strict separation of powers doctrine can contribute to the overall goal of preventing tyranny; whereas destructive breaches pose a threat to that goal. Many states with constitutions based upon the tripartite system have experienced the development of many administrative organs that carry out many of the daily tasks of government. These agencies do not fit easily into any of the three branches.

The UK possesses governmental bodies, some of which are headed by government Ministers, which do not fit exclusively into either the executive, judiciary or legislature. Although very few countries adhere rigidly to the separation of powers doctrine, most constitutional systems do attempt some form of demarcation between the legislature, executive and judicial organs of government to avoid abuse of power by any one of the three branches.

Separation of Powers and the Constitution

The exact position of the doctrine of the separation of powers within the UK constitution is unclear. There are various different views as to whether the doctrine is part of the UK constitution. In Hinds v The Queen [1977] AC 195, Lord Diplock described

'the basic concept of separation of legislative, executive and judicial power as it had been developed in the unwritten constitution of the United Kingdom'(at 212).

In The English Constitution (London, 1867) Bagehot argues that the

"efficient secret of the English Constitution may be described as the close union, the nearly complete fusion, of the executive and legislative powers".

There is a significant overlap in the work of the executive and the legislative branches, with the executive exerting a substantial influence over the work of Parliament. This creates a threat to the ability of the separation of powers doctrine to effectively prevent the abuse of power in the UK. At the same time, there are examples where separation of powers is strictly adhered to, such as in relation to the independence of the judiciary. Opinions vary on how best to achieve the balance between the separation of government institutions and the need for those institutions to work together and cooperate. There is no single answer to achieving the right balance.

In R v Secretary of State for the Home Department, ex p Fire Brigades Union [1995] 2 AC 513 the Home Secretary was unwilling to invoke powers under s 171(1) Criminal Justice Act 1988 to bring into force a new scheme to offer compensation to victims of criminal offences. Instead, he announced a different tariff scheme under the royal prerogative. The case raised the question whether this use of the prerogative was consistent with the powers Parliament had conferred.

A three-fifths majority of the House of Lords held that the Home Secretary had exceeded his powers. The majority found that he had acted unlawfully in introducing the tariff scheme in a way that frustrated the statutory scheme. He remained under a duty to consider bringing the statutory scheme into force. The minority judgment held that since the legislation was not yet in full force, it was inappropriate for the court to intervene, making the issue a political one. Judicial intervention in their view would involve a breach by the judiciary of the separation of powers doctrine. The case illustrates how a different emphasis on one particular aspect of the separation of powers can lead to a different conclusion. The majority emphasised the importance of the executive not overreaching its powers, whereas the minority considered the non-interference of the judiciary in areas beyond its concern as the overriding factor. In R (Miller) v The Prime Minister [2019] UKSC 41, the Supreme Court held that advice to prorogue Parliament was unlawful where its effect was to prevent Parliament from legislating or scrutinising the executive without reasonable justification.

The important aspect regarding the separation of powers doctrine, thus, is less in its specific formulation, but in its ability to prevent the abuse of power of any one of the three branches of government. Although appearing simplistic, complexity is introduced when various parts of the doctrine are interpreted as taking precedence over others and the need to balance the doctrines checks on abuse of powers with the need for branches to co-exist in relationship with one another. The three branches of government will now be examined in further detail.

The Institutions - the Executive

The executive at UK level is comprised of the Head of State, or monarch, the Prime Minister, the Cabinet, Secretaries of State, ministers of the Crown, departments of state and the armed forces. Executive functions are also exercised by devolved administrations, local authorities, the police and other public bodies.

The Prime Minister is appointed by the Head of State. After a General Election, the incumbent remains in office unless he or she resigns. When a new Prime Minister is needed, the monarch invites the person most likely to command the confidence of the House of Commons to form a government.

The powers of the executive

Primarily the executive has a vast array of statutory powers afforded to it by Parliament. Since Parliament is unable to legislate for every eventuality, the Inquiries Act 2005 makes provision for inquiries into matters of public concern, so that every time something of public concern occurs, Ministers have the power to set up an inquiry within specific parameters, instead of Parliament having to legislate each time to deal with the specific incident.

The Prime Minister's powers come from the Royal Prerogative and statute. He or she has a role in advising the monarch on:

• the exercise of prerogative powers such as the appointment of ministers;
• certain judicial appointments, including the judges of the Supreme Court, for whom the Prime Minister must recommend the person selected under the Constitutional Reform Act 2005.

The Prime Minister also recommends senior appointments in the armed forces to the monarch, and recommends honours or life peerages. The Prime Minister also makes decisions regarding the Cabinet, such as determining its size, controlling its agenda and creating and disbanding Cabinet Committees. The Home Secretary appoints the head of MI5, and the Foreign Secretary appoints the heads of MI6 and GCHQ. Responsibility for advising the King on Church of England appointments normally made on the Prime Minister's advice has been temporarily transferred to the Lord Chancellor.

The Cabinet is chosen by the Prime Minister and appointed by the monarch. It is made up of around 20 members, but this number varies. The Cabinet functions to consider questions which concern the collective responsibility of government and are of critical importance to the public. The Cabinet determines the contents of the King's Speech, the government's legislative programme and the broad economic policy, which establishes the basis of the Chancellor of the Exchequers budget.

Standing and ad hoc Cabinet Committees are empowered to deal with matters of current importance. The Prime Minister chairs Cabinet meetings and keeps the monarch informed of government business at regular audiences.

In AG v Jonathan Cape [1976] QB 752, [1975] 3 All ER 484 Lord Widgery CJ described 'collective cabinet responsibility' as meaning that any policy decision reached by the Cabinet had to be supported by all members of the Cabinet, unless they were willing to resign. The Ministerial Code applies collective responsibility to all ministers unless it is explicitly set aside.

The permanent Civil Service is required to act in a way that is independent of any political party; the employees will work for whichever political party is in government at the given time. The advantage of a politically neutral civil service, as laid down for in the Northcote-Trevelyan, Report on the Organisation of the Permanent Civil Service (House of Commons, 1854), is that it provides an element of stability despite political change in Parliament. The Constitutional Reform and Governance Act 2010 provides the statutory basis for the management of the civil service; it requires civil service codes and, subject to exceptions, selection on merit on the basis of fair and open competition. Special advisers are exempt from the requirement of political impartiality.

Devolution

Devolution in the UK means that legislative and executive powers have been conferred upon the legislatures and administrations within Scotland, Wales and Northern Ireland.

The Scottish Government was established by part II Scotland Act 1998; it consists of the First Minister, other ministers appointed under section 47 and the Scottish Law Officers. The First Minister is a member of the Scottish Parliament, nominated by its members and appointed by the monarch. With Parliament's agreement, the First Minister appoints the other ministers with the monarch's approval and recommends the Law Officers for appointment by the monarch. A referendum held in Scotland in 2014, on independence from the UK, resulted in a 'No' Vote.

The Government of Wales Act 1998 (section 1) established the National Assembly for Wales. Under sections 52-55 the Assembly elected a First Secretary, who appointed Assembly Secretaries. The Act also made provision for the Welsh Administration Ombudsman and for changes to the functions of the Welsh Development Agency, the Development Board for Rural Wales, the Land Authority for Wales and Housing for Wales.

The Government of Wales Act 2006 established the Welsh Assembly Government, now the Welsh Government, which is separate from the legislature, Senedd Cymru (the Welsh Parliament). It deals with the appointment and remuneration of the First Minister and other Ministers, creates the office of Counsel General, and makes provision for appointments and civil service staff. The Senedd nominates the First Minister for appointment by the monarch. The First Minister appoints other Welsh Ministers with the monarch's approval.

The First Minister and deputy First Minister jointly lead the Northern Ireland Executive. They are nominated under the power-sharing provisions of the Northern Ireland Act 1998. Other ministerial portfolios are allocated between parties by the d'Hondt formula, except for the Minister of Justice, whom the Assembly elects with cross-community support. The Northern Ireland Act 2000 provided for suspension of devolution. The Northern Ireland Act 2006 made provision for preparations for its restoration, which took effect on 8 May 2007.

Local Government

Local Government in England includes county and district councils in two-tier areas and single-tier councils elsewhere, including London boroughs. The legislation includes the Local Government Act 1972, the Local Government Act 1985 and the Local Government Act 1992. The London Government Act 1963 established Greater London. The Greater London Authority Act 1999 established the Greater London Authority. Section 323 altered the Metropolitan Police District to cover Greater London apart from the City of London, the Inner Temple and the Middle Temple.

In Wales, the Local Government (Wales) Act 1994 established twenty-two Unitary Authorities in Wales.

Scotland is made up of thirty-two council areas, including the three island council areas, under the Local Government etc. (Scotland) Act 1994.

Northern Ireland was defined by reference to the parliamentary counties of Antrim, Armagh, Down, Fermanagh, Londonderry and Tyrone and the parliamentary boroughs of Belfast and Londonderry. Section 43(2) of the Northern Ireland Constitution Act 1973 adopted that definition from section 1(2) of the Government of Ireland Act 1920. For local government, Northern Ireland has eleven districts under the Local Government (Boundaries) Act (Northern Ireland) 2008.

The Police

The police forces in the UK are part of the executive. The Police Act 1996 and the Police Reform Act 2002 contain provision for the organisation of the police forces and police areas in England and Wales. Under the Police Reform and Social Responsibility Act 2011, elected police and crime commissioners or mayors exercising those functions set police and crime plans and hold chief constables to account. In London, the Mayor's Office for Policing and Crime oversees the Metropolitan Police and the Common Council is the police authority for the City of London. Chief officers retain direction and control of their forces.

The Institutions - Parliament (Legislature)

Parliament is the institution that is responsible for the creation of new legislation, the scrutiny of bills and of holding the executive to account. The UK Parliament is located in Westminster in London and is comprised of the monarch, the House of Commons (or lower house) and the House of Lords (the upper chamber). Local voters in general elections elect members of Parliament within the lower house. A bill becomes an Act when it receives royal assent.

House of Commons

Members of the House of Commons are elected directly by registered parliamentary electors, including eligible British, Irish and qualifying Commonwealth citizens. The Dissolution and Calling of Parliament Act 2022 repealed the Fixed-term Parliaments Act 2011 and restored the power of the monarch to dissolve Parliament at the Prime Minister's request. Unless dissolved sooner, Parliament dissolves on the fifth anniversary of its first meeting.

Parliament has come under criticism for its ability to represent the will of the people in the UK, in that:

1. The current system of elections does not represent all parties equally within Parliament
2. The House of Lords is unelected, however, it plays an important role in the making of the countries laws;
3. There are insufficient women and ethnic minority MPs to represent the electorate.

There is no particular consensus on how MPs should represent their constituents. There is no agreement in political opinion as to whether the MP should attempt to represent the wishes of the majority of their constituents or that the constituents hand over power to their MP to use their own judgment to vote in the way they feel is most appropriate.

House of Lords

The second and upper chamber is the House of Lords, whose members are the Lords Temporal and the Lords Spiritual. The vast majority of peers are life peers who are appointed to the chamber for life, although membership may end earlier, for example by retirement or expulsion. The Life Peerages Act 1958 provided for life peers, including women, to sit in the House of Lords. The House of Lords Act 1999 removed the right of most hereditary peers to sit in the House, retaining an exception for ninety-two. The House of Lords (Hereditary Peers) Act 2026 removed that exception at the end of the parliamentary session on 29 April 2026. Reforms to the House of Lords by the 1997 Labour government led to a significant reduction of the number of hereditary peers who used to significantly outnumber the life peers and were unelected and mainly Conservative party members. There are also up to twenty-six bishops and archbishops (referred to as Lords Spiritual) of the Church of England, who sit by virtue of their ecclesiastical office.

The democratic legitimacy of the House of Lords has been drawn into question since they are not an elected body through the system of universal suffrage and cannot be removed by the electorate, since their role in the House of Lords is through appointment or ecclesiastical office. The House of Lords is going through a long-term period of reform, and a number of proposals have been made to improve its democratic legitimacy.

Functions of Parliament

The main areas of Parliamentary responsibility include enacting legislation, scrutinising the executive, controlling public spending and addressing the concerns of constituents. Parliament's legislative role is the enactment of primary and scrutiny of secondary legislation made under powers delegated by Parliament. Legislation is said to respond to social, economic and political changes in society, which require new laws to be made. The House of Commons Select Committee on Procedure considered the parliamentary timetable in its First Report of 1986-87, A Parliamentary Calendar (HC 157).

The House of Lords and the House of Commons perform distinct functions in relation to the creation of legislation. This is known as a bicameral system with two chambers that perform different functions. The House of Lords acts as a check on the abuse of power by the executive, by scrutinising and revising bills. Under the Parliament Acts 1911 and 1949, a certified Money Bill passed by the Commons and sent to the Lords at least a month before the end of the session can receive royal assent if the Lords has not passed it unamended within a month. Most other public bills originating in the Commons can pass without that agreement if the Commons passes them in two successive sessions, the Lords rejects them in both, and at least a year elapses between the second reading in the first session and passage by the Commons in the second. The bill must reach the Lords at least a month before the end of each relevant session. This procedure cannot be used for a bill extending the maximum duration of Parliament beyond five years.

The Institutions - The Judiciary

The primary role of the Judiciary is to adjudicate on legal disputes that are brought before courts and tribunals in the UK. The primary sources of law in the UK are legislation and judicial decisions. The judges' role is in the interpretation of legislation and in the development of the common law. Judicial independence is of primary importance, it has implications for its relationship with the executive and Parliament, and provides public confidence in the judge's ability to adjudicate on disputes in an impartial manner. 

At first instance, the court must decide the case on the facts, make a determination of the relevant law and then apply the law to the facts that are found. In judicial review the court normally examines the lawfulness of the decision on the facts available to the original decision-maker. Facts are determined by the provision of evidence, often through witness statements or medical evidence.  A determination of the law can be a complex issue, the case may raise points of law relating to new statutory authorities, which have not been evaluated before. These cases may end up in the appeal courts if the parties feel that a mistake has been made regarding statutory interpretation. An application of the facts to the law in a criminal case for example requires the tribunal of fact, such as a jury or magistrates, to determine whether the essential legal elements of that particular offence are present within the factual scenario as determined by the evidence presented.

Judicial Review

One of the primary roles of the court systems is in holding the executive to account, by introducing accountability for the performance of public functions. This involves the checking, controlling and regulating of those functions. The Criminal Justice and Courts Act 2015, combined with cuts in legal aid, have made it harder to bring a case for judicial review, and hence presented the risk that government accountability has been undermined. 

In England and Wales, the Senior Courts Act 1981 and Part 54 of the Civil Procedure Rules govern judicial review in the High Court. A claimant needs a sufficient interest in the matter and the court's permission to proceed on an arguable ground. A claim must be filed promptly and normally within three months, although some claims have shorter time limits. A victim can also challenge a public authority's breach of a Convention right under sections 6 and 7 of the Human Rights Act 1998.

In Council of Civil Service Unions v Minister for the Civil Service [1985] AC 374, Lord Diplock outlined three grounds upon which administrative action can be challenged via judicial review:

• Illegality
• irrationality
• procedural impropriety

The role of Lord Chancellor is where the judiciary is said to meet the executive, prior to April 2006 the Lord Chancellor was head of the judiciary of England and Wales and had the power to appoint judges. That responsibility passed to the office of Lord Chief Justice, whose present holder is styled Lady Chief Justice. The Lord Chancellor is a Cabinet minister; s.3 Constitutional Reform Act 2005 for the first time places a legal duty on government ministers to uphold the independence of the judiciary. The Ministry of Justice was created on 9 May 2007 and has responsibilities including courts, prisons and probation in England and Wales.

The Human Rights Act

The Human Rights Act 1998 (HRA) gives effect to the Convention rights defined in section 1, drawn from the European Convention on Human Rights (ECHR) and certain protocols, in UK law.

• When determining a question concerning a Convention right, section 2 HRA requires a UK court or tribunal to take account of relevant Strasbourg case law, including judgments of the European Court of Human Rights (ECtHR).
• Section 3 HRA provides that, so far as possible, courts must read and give effect to primary and subordinate legislation in a manner that is compatible with the Convention rights.
• If not possible to interpret in accordance with section 3, section 4 HRA enables the higher courts to grant a declaration of incompatibility stating that a provision of primary legislation is incompatible with a Convention right. This also applies to subordinate legislation where primary legislation prevents removal of the incompatibility. The declaration does not affect the validity or continuing operation of the provision or bind the parties to the proceedings.

In R v A (No.2) [2001] UKHL 25;[2002] 1 AC 45 the defendant was accused of rape, but argued consent as a defence, arguing he had had previous sexual relations with the complainant. Section 41 of the Youth Justice and Criminal Evidence Act 1999 introduces the concept of four 'gateways', under which the court may give the defence leave to adduce evidence or ask questions about a complainant's sexual behaviour in trials for sexual offences. In R v A (No.2) the accused argued that none of these four gateways would allow in the evidence of a prior sexual relationship between the accused and complainant. The accused introduced Article 6 of the ECHR on the right to a fair trial, arguing that if the sexual history evidence was withheld from the jury, then he would not receive a fair trial. The House of Lords interpreted section 41(3)(c) under section 3 HRA to allow evidence of a prior sexual relationship where it was so relevant to consent that excluding it would endanger the fairness of the trial.

The UK remains a party to the ECHR following its withdrawal from the EU. The HRA remains in force. The ECtHR can find that a state has breached the Convention. Its final judgment binds the state concerned but does not itself overturn a domestic judgment. In Chahal v UK [1996] 23 EHRR 413, and Saadi v Italy [2008] ECHR 179, the ECtHR found that terrorist suspects could not be deported if there were substantial grounds for believing that they faced a real risk of torture or inhuman or degrading treatment or punishment in the receiving country, regardless of the threat they posed.

The European Union

Although the UK left the European Union on 31 January 2020, the EU is still of considerable relevance in UK law and governance. As a result of the economic devastation of the European continent after the Second World War, Winston Churchill called for a "kind of United States of Europe" in 1946. The treaties establishing the European Economic Community (EEC) and the European Atomic Energy Community (Euratom) were signed in Rome in 1957, and the treaty establishing the European Coal and Steel Community (ECSC) was signed in Paris in 1951. The UK did not join the three communities until 1973.

The EEC was renamed the European Community by the Treaty on European Union (the Maastricht Treaty), which also renamed the EEC Treaty (Treaty of Rome) the EC Treaty. The EC Treaty was later to become known as the Treaty on the Functioning of the European Union (TFEU). The Lisbon Treaty provided for the Union to succeed the European Community. The EU institutions listed in Article 13 TEU are the European Council, the Council of the EU, the Commission, the European Parliament, the Court of Justice of the European Union (CJEU), the European Central Bank and the Court of Auditors.

The TEU was signed at Maastricht in the Netherlands in 1992 and established the European Union when it entered into force on 1 November 1993. The TEU made significant changes to the provisions of the EC Treaty, including strengthening the powers of the European Parliament and establishing the foundations of the economic and monetary union. The first stage removed barriers to movement of capital within EU Member States from July 1990. Stage 2 aimed to bring about the convergence of European economies and began on 1 January 1994. Stage 3 has involved the establishment of irrevocably fixed exchange rates for the participating currencies and the introduction of the single currency, the euro, from 1 January 1999.

The UK never joined the single currency. Under its treaty opt-out it was not required to adopt the euro. In the EU referendum of 23 June 2016, voters chose by a margin of 52% to 48% to leave the EU. On leaving the EU, the UK ceased to be represented in its institutions. The transition period ended on 31 December 2020. The Withdrawal Agreement and the Trade and Cooperation Agreement govern much of the relationship. Section 7A of the European Union (Withdrawal) Act 2018 gives domestic effect to rights and obligations under the Withdrawal Agreement, including the application of specified EU rules in Northern Ireland under the Windsor Framework. The retained EU law which remained at the end of 2023 became known as assimilated law.

The Lisbon Treaty, which was signed on 13 December 2007 and entered into force on 1 December 2009, was the source of significant constitutional reform within the EU. Judicial review proceedings were brought in R (on the application of Wheeler) v Office of the Prime Minister [2008] EWHC 1409 (Admin) in which the claimant sought a declaration that the UK government had acted unlawfully on deciding not to hold a referendum on the Lisbon Treaty.  The claimant was defeated on the fact that the promise of referendum by the Labour government was made in relation to the Constitutional Treaty, which was not adopted. The court held that the promise did not give rise to an enforceable legitimate expectation of a referendum on the Lisbon Treaty. The Lisbon Treaty was given domestic effect under the European Communities Act 1972 as amended by the European Union (Amendment) Act 2008.

The European Council

The European Council has no legislative function, but is to 'define the general political directions and priorities of the [EU]'(Art 15(1) TEU). It is made up on heads of state or government of Member States, its President, and the President of the Commission. The Presidents role is to chair and progress the work of the European Council, to facilitate cohesion and consensus and to report to the European Parliament after Council meetings. The President also represents the Union at that level on issues concerning common foreign and security policy, without prejudice to the powers of the High Representative.

The Council of the EU

The Council is the hardest of the EU institution to place within the three branches of government advocated within the separation of powers doctrine. It consists of a ministerial representative of each Member State and shares legislative and budgetary functions with the European Parliament. The Council considers legislation initiated by the Commission.

The Commission

The Commission exercises executive functions and normally initiates legislation. It is made up of a Commissioner from each of the Member States, each with a particular area of responsibility (e.g. trade and industry, competition). The Commissioner is required to act independently of all national governments. The Lisbon Treaty provided for a smaller Commission unless the European Council unanimously decided otherwise. European Council Decision 2013/272/EU retained one Commissioner per Member State.

The Parliament

The European Parliament consists of directly elected representatives of EU citizens to exercise powers endowed upon it under the TEU and TFEU. In the UK, elections to the European Parliament were governed by the European Parliamentary Elections Act 2002. The Act, now repealed, provided for a system of proportional representation for election of MEPs. Article 14(2) of the TEU provides that the European Parliaments membership shall not exceed 750, in addition to the President of the European Parliament. There are 720 seats for the 2024-2029 term.

The Treaties provide for an 'ordinary legislative procedure' and special legislative procedures. The former applies to a co-decision procedure set out in Article 294 TFEU. It normally begins when the Commission submits a proposal for legislation to the Parliament and the Council. Parliament and the Council must both agree on the text. Under special procedures, their respective roles depend on the Treaty provision involved.

The Court of Justice of the European Union

Under the Treaty of Lisbon, the Court of Justice of the European Union became the name of the EU judicial institution in 2009. It sits in Luxembourg and comprises the Court of Justice and the General Court. The Court of Justice has one judge per Member State (Art 19(2) TEU), and the General Court has two. The rules of the Court of Justice allow it to sit as the full court, in chambers or as a Grand Chamber. The primary function of the Court is to ensure that in the interpretation and application of the Treaties, the law is observed.

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