The case against parliamentary sovereignty

As a principle it is eccentric, antiquated—and doesn’t match the realities of how modern Britain is governed

December 30, 2021
Academic AV Dicey believed  sovereignty in England has always been understood as being essentially unlimited and indivisible, but there is no overwhelming evidence to support this. Image: Aclosund Historic / Alamy Stock Photo
Academic AV Dicey believed sovereignty in England has always been understood as being essentially unlimited and indivisible, but there is no overwhelming evidence to support this. Image: Aclosund Historic / Alamy Stock Photo

Is an unhealthy adherence to parliamentary sovereignty endangering the future of the UK? This might seem a strange question. Why indulge in abstruse constitutional concerns in an era when environmental catastrophe and Covid-19 present truly troubling threats? But the future of the UK union is no arcane concern. It is not a secret that there is disquiet among the UK’s devolved nations. Will the UK even continue to exist by the end of this decade, or might it be reduced to a rump, a diminished UK made up of just England and Wales? To pursue this reflection, we need to consider the paradoxes and problems of parliamentary sovereignty and devolution.

It is well known that the UK is one of a tiny handful of countries lacking a codified constitution. Parliamentary sovereignty instead provides a baseline constitutional principle. One of the drivers of Brexit was to “take back control” from EU institutions that were supposedly intruding on this sovereignty. But the UK’s concept of parliamentary sovereignty is very singular and eccentric, for it requires absolute, unlimited and indivisible legislative power, whereby Westminster legislation takes priority over any other law, constitutional principle or body, however hallowed or crucial. It is hard to find another state in the world that operates such an extreme doctrine.

A not-so-illustrious history

First of all, it is worth noting that parliamentary sovereignty does not have a long pedigree. It dates only as far back as the Glorious Revolution of 1688, or possibly as recently as the 18th or 19th century. There is no mention of it in important constitutional documents such as the English Bill of Rights of 1688, nor is there mention in the Acts of Union of Scotland and England of 1706-1707 of a sovereign, illimitable parliament. It was only later, with the domination of British constitutional law by Oxford academic AV Dicey in the late 19th century, that parliamentary sovereignty really took hold.

Dicey insisted that parliamentary sovereignty was a matter of logic, and that “limited sovereignty” was a “contradiction in terms.” If true, this would rule out federalism, where sovereignty is shared between a national federal centre and states or provinces.

But why must sovereignty be understood only as unlimited and indivisible? Many others understand it differently. Divisible sovereignty was well understood by the framers of the US federal constitution. Dicey’s answer was that sovereignty was always understood in this way in England, but there is no overwhelming evidence for this. For many centuries, there existed a different tradition of the English constitution dating from medieval times, whose essence could be distilled to three main components: that the fundamental law was unwritten, legally supreme and also, at least on some occasions, judicially enforceable.

Indeed, some parts of the UK have always been reluctant to recognise the supposed orthodoxy of parliamentary sovereignty. For example, in the 1953 Scottish case of MacCormick v Lord Advocate, the senior Scottish judge, Lord Cooper, stated: “the principle of the unlimited sovereignty of parliament is a distinctively English principle which has no counterpart in Scottish constitutional law...” Many Scots of different political persuasions stand by an indigenous Scottish tradition of popular sovereignty claimed to date back to the Declaration of Arbroath, signed in 1320 but still “active” today. When the English and Scottish parliaments united in 1707, a new parliament—that of Great Britain—was formed, rather than the Scottish parliament being absorbed into the English one. Therefore, it may seem illogical to assert that the English principle of the sovereignty of parliament should reign supreme—and that Scottish notions of sovereignty of the people should be ignored.

The beginning of devolution

Devolution has since made the principle of parliamentary sovereignty even more contentious. For to perceive the UK as a unitary state, dominated by an absolute concentration of power in Westminster, is to misunderstand how the UK is really governed.

Devolution was introduced in 1998 as a means of giving new powers to the UK’s constituent nations, with the hope of pacifying growing nationalist movements. Each of the Devolution Acts for Scotland, Wales and Northern Ireland include a provision that the power of the British parliament to make laws for the devolved nations and territories remains unaffected. In this way, devolution was crafted to specifically protect parliamentary sovereignty.

However, two factors relating to how devolution has evolved since then show how it might yet present a genuine challenge to this constitutional principle. First, generally speaking, a “reserved powers” model of devolution now operates in Scotland, Wales and Northern Ireland, which means that all legislative power is devolved, except those matters expressly reserved to the UK in the devolution statutes. This factor became very salient with Brexit. Second, in the earlier years of devolution, the UK government accepted a fair amount of “permissive autonomy,” meaning there was considerable self-rule exercised by devolved institutions. In this respect, devolution gave rise to something akin to the “self-rule” of federalism, with “quasi-sovereign” institutions in its devolved territories.

“It is hard to find another state in the world that operates such an extreme doctrine as parliamentary sovereignty”

But devolution still lacks the crucial “shared rule” principle that characterises federalism. In the UK, reserved areas—like foreign affairs, monetary policy and trade—tend to overlap with powers that would typically be shared under federalism. Yet the power to act in these areas remains at London’s discretion, and any freedom of manoeuvre for devolved governments is, like relations between the UK and the devolved nations as a whole, almost entirely informal, based on concordats, memoranda of understanding and a somewhat dysfunctional Joint Ministerial Committee of executives that rarely met before Brexit. Devolved institutions lack enforceable legal powers in these reserved areas. Even legislative relations are regulated only by the Sewel convention—by which the UK parliament agrees to not normally legislate on devolved matters without the consent of the devolved legislatures. And this was held by the UK Supreme Court, almost inexplicably (especially so as since 2016 the convention had been expressed in legislation), to be legally unenforceable.

As a result, perhaps it is not surprising that the term “Schrödinger’s devolution” has been used to describe devolution in the UK—namely “the idea that, since 1999, Scotland, Wales and Northern Ireland both have and have not experienced fundamental constitutional change, on which claims to territorial autonomy can be founded.” Devolution has thus been Janus-faced, both increasing devolved autonomy as well as containing it.

Two views of the cathedral?

There are at least two ways of understanding how devolution operates in the UK.

One view—typically that of the UK government—understands the UK as a unified, centralised state, without critical territorial differences and with a constitutional foundation of absolute parliamentary supremacy. Devolved authorities have no legal rights in reserved areas and, at most, may be consulted as a matter of courtesy or goodwill. This attitude explains why the EU referendum vote was counted UK-wide, with no attention to regional variation. For adherents, Scotland’s (or Northern Ireland’s) vote to remain in the UK had no constitutional relevance beyond their contribution to the total number of ballots cast across the British Isles. And this interpretation of our constitution has only been strengthened by Brexit.

However, an alternative approach views the UK as a union state—multinational and multigovernmental—founded on treaties (such as the treaties of union of Scotland and England, and the 1998 Good Friday agreement). It interprets the UK as a union reliant on ongoing consent. It also notes the importance of constitutional conventions (rather than “black letter law”) that require the government to exercise self-restraint. The Good Friday agreement sets out complex provisions for Northern Ireland regarding cross-community consent, and also a role for the Republic of Ireland. The Northern Ireland Act provides that a change in the constitutional status of Northern Ireland may only occur with the consent of the majority of people in Northern Ireland voting in a pollthus allowing popular sovereignty to precede parliamentary sovereignty. The Scotland Act 2016 and Wales Act 2017 declared the permanence of the Scottish and Welsh parliaments and governments: provisions which, if they are to have any meaning, fly in the face of orthodox constitutional law’s assertion of parliamentary sovereignty.

This second understanding promotes a more nuanced interpretation of sovereignty, noting a growing adherence to popular sovereignty through the use of referendums. It kindles claims of legitimacy that compete with parliamentary sovereignty.

Brexit and devolution

These two different understandings of the constitution muddled along together for the earlier years of devolution, even surviving the maelstrom of the 2014 Scottish independence referendum. What really put relations under strain was Brexit, especially given that both Scotland and Northern Ireland voted to remain in the EU but Wales and England (which of course has the great majority of the UK’s population) did not. However, there was no possibility of any variegated approach to Brexit, because the UK government insisted that the UK exit the EU as one state, with the UK government in charge of Brexit negotiations, which were considered a reserved matter.

Brexit undermined the “reserved powers” model of devolution. In the act of taking back control from the EU, UK government legislation (in an earlier draft of the EU Withdrawal Act 2018) expressed an intention to return legislative authority to Westminster by default, even when the powers in question were devolved, such as those relating to agriculture and the environment. This was justified as necessary to ensure a functioning UK internal market post-Brexit, but even a redraft of the relevant provision could not persuade the Scottish parliament to grant its legislative consent to the Act, nor prevent accusations of a “power grab” by London. Indeed, Holyrood was later joined by the Welsh and Northern Ireland legislatures, all of which refused consent to the 2020 EU Withdrawal Agreement Act. Both the Scottish and Welsh legislatures also refused consent to the UK Internal Market Act 2020.

This did not stop that legislation from being adopted, given the UK Supreme Court’s view—expressed in the first Gina Miller case—that the Sewel convention, even set out in legislation, nonetheless remained a convention only and not legally binding. It was therefore legal for the UK to adopt legislation in the absence of consent from the devolved parliaments—legal, but possibly not constitutional.

No longer at ease

The UK no longer has an empire. It has also left the EU. But it is still a composite or union state of four nations. If it is to function, then its constitutional structures must acknowledge this variety.

Britain has a supposedly flexible constitution, full of synergies and conventions to suit every situation. Yet in practice, most of this flexibility is political and exercised only when it suits: the UK often retreats into a hard, minimal legal constitutional shell—a highly eccentric understanding of parliamentary sovereignty as impermeable and unshareable.

This notion perceives sovereignty as indivisible, and impossible to share between different levels of British government. Dicey judged federalism as too fragmentary, and too debilitating, for Britain. But he never had a good answer as to why the UK must cleave to this extreme notion of sovereignty when other states (such the US, or Germany) do not. And because the UK has a fused system, with the executive drawn from parliament, this understanding of sovereignty empowers the government, at least where it has a majority. Dicey himself conceded that parliamentary sovereignty was “an instrument well adapted for the establishment of democratic despotism”—and indeed even abandoned the theory when it suited him, such as in his opposition to Home Rule for Ireland, even though it had parliamentary support.

There is, it seems, nothing that a government with a parliamentary majority may not do. It may abolish human rights legislation, reduce civil liberties, constrict the opportunities for judicial review, and force through legislation against the will of the devolved parliaments, taking them out of the EU. Provisions such as the Sewel convention might be seen as valuable constitutional glue, ensuring that Britain’s constitution functions for the benefit of all. The problem is that such conventions are not legally binding. If they are ignored, there is no legal recourse. If the “good chaps” (or, we might add, “chapesses”) are no longer observing the rules of government, then parliamentary sovereignty is allowed to run riot.

One may think a Scottish or Welsh parliament declared “permanent” in UK legislation safe, but given that the orthodox doctrine of parliamentary sovereignty is understood to mean that the UK parliament may never limit itself—what is to stop a future Westminster statute abolishing these institutions anyway?

Lessons from history

Does this persistent attachment to parliamentary sovereignty risk the breakup of the UK? It is hard to see how present-day competing claims of robust unionism and nationalism will be resolved. Small-scale reforms are unlikely to satisfy nationalists, but the more radical step of federalism is usually ruled out in the UK, as it requires shared sovereignty, said to be impossible due to parliamentary sovereignty and English dominance in population and economic power.

History does not supply comforting examples. Disputes over the sovereignty of the Westminster parliament led to the loss of the British North American colonies. Relations between the UK and Ireland had become violent before the Irish Free State was formed. Nobody wants to live in a state of perpetual constitutional crisis. Surely it is preferable to embrace a more nuanced concept of sovereignty.