“The principle of parliamentary sovereignty means that Parliament has the right to make or unmake any law whatever and further that no person or body has a right to override or set aside the legislation of Parliament.”

A.V. Dicey formulated his doctrine of parliamentary sovereignty in his Introduction to the Study of the Law of the Constitution, first published in 1885.

But interest in the idea — or at least the phrase — has undergone a marked revival thanks to the Brexit controversy. And from both sides. Brexiteers vehemently campaigned for the restoration of parliamentary sovereignty from its subordination to the supranational claims of the EU and the European Court of Justice. Remainers, equally enthusiastically, latched onto the idea to justify a Remainer parliament resisting the Leave verdict of the 2016 referendum.

So far, so confusing. In fact, it only takes a moment to realise that the two sides weren’t really arguing about parliamentary sovereignty in its strict Diceyian sense at all; they were doing something much more interesting and debating the nature and history of Parliament itself.

The English parliament, of which the post-Union British parliament is a mere extension, develops in the thirteenth century in the aftermath of Magna Carta. There are two key, sharply contrasting figures in the story: Simon de Montfort, “the first leader of a political movement in English history”, driven, devout, principled yet deeply self-interested, and his nemesis, Prince Edward, later King Edward I, who defeated, killed and dismembered de Montfort at the Battle of Evesham.

De Montfort, in the brief period when he held the royal family prisoner and was the real ruler of England, first summoned representatives of the counties and towns to parliament in 1265. Thirty years later, Edward, by this time a deeply experienced king, summoned the same groups to the so-called “Model Parliament” of 1295 and ushered in the House of Commons in recognisably modern form.

The action is the same but the intention was fundamentally different. De Montfort saw parliament as a necessary limitation on the despotic powers of the king; Edward, on the other hand, realised that parliament could be fashioned into an instrument to strengthen royal government and make it more efficient. Parliamentary statute carried out Edward’s great programme of legal reform; parliamentary taxation financed, relatively painlessly, his wars of imperial conquest against Wales and Scotland.

The two contrasting approaches of De Montfort and Edward I condition parliament to the present: they are its warp and weft. 

Parliament as opposition supplies the great moments of parliamentary drama beloved of Victorian historians from de Montfort himself, through the Civil War to the Glorious Revolution. 

Parliament as instrument of government produces the soberer materials of revisionist historians like Conrad Russell and is the reason that the English/British parliament survived whereas the representative assemblies of all the other major European states atrophied and died.

But everybody agreed the parliament’s first job was to protect England and Englishmen. De Montfort, though he was French, campaigned vehemently against “aliens”; and kings, however pious, legislated against the interference of Italian popes in the English Church.

These tendencies culminated in the reign of Henry VIII. As early as 1515, the young king declared “we be informed by our judges that we at no time stands so highly in our estate royal as in the time of Parliament”. 

Twenty years later Henry’s determination to divorce his first wife, Catherine of Aragon, and marry Anne Boleyn turned these high-sounding phrases into the sober reality of statute. 

The act in restraint of appeals of 1533 declared that “this realm of England is an empire, governed by one Supreme Head and King, furnished with entire power to render justice and final determination to all manner of folk in all causes without restraint or provocation to any foreign princes or potentates of the world”. 

Johnson’s government plans to rebalance the economy. At least as important is to rebalance the constitution

At his trial in 1535 Sir Thomas More claimed that the Reformation parliament had gone beyond its powers. The common consent of Christendom, he insisted, gave the headship of the church to the pope. An English parliament could no more transfer the title of Supreme Head to the King than London, as a single city, could presume to legislate for all England.

He was answered by the Lord Chief Justice with a typical piece of English legal positivism: “If the act of parliament be not unlawful, then is not the indictment in my conscience insufficient.” This is Dicey in sixteenth-century English: the law is what parliament says it is and conscience be damned.

In other words, Brexiteers are right: parliamentary sovereignty is inextricably linked with national sovereignty. They stand and fall together and the one is meaningless without the other. As lord chancellor Kilmuir pointed out to prime minister Edward Heath during the negotiations to join the EEC, “The surrenders of sovereignty involved are serious ones … [They] ought to be brought out into the open now because, if we attempt to gloss over them at this stage, those who are opposed to the whole idea of our joining will certainly seize on them with more damaging effect later on.”

Rarely has a political prophecy been more amply fulfilled. But what of the Remainer deployment of parliamentary sovereignty? This is much more contentious. For Remainers not only suppressed the connection between parliamentary and national sovereignty, they also focused only one of the Janus-faces of parliament, that of Montfortian opposition. 

Which is why they are so enthusiastic about the seventeenth century when the usually closely woven fabric of parliamentary history was torn apart by strife, stalemate and civil war. Brenda Hale, the then president of the Supreme Court, happily recalled her schoolgirl interest in seventeenth-century history. The key precedents she cited in the court’s prorogation judgement were early Stuart ones; the Fixed-Term Parliament Act, which was the precondition for the “seizing of the initiative” by the 2017-19 House of Commons, was an echo of the act of 1641 that parliament could not be dissolved without its own consent which similarly entrenched the position of the Long Parliament; Speaker Bercow, with his high-flown talk of freeing the Commons from the grip of the executive, was consciously modelling himself on William Lenthall, the Speaker of the Long and Rump Parliaments (Lenthall even tried, with conspicuous lack of success, to extract a peerage from the Restoration government!); while Dominic Grieve, with his shameless procedural chicanery, clearly aspired to be an anti-leader of the Commons on the lines of John Pym.

This deliberately one-sided view of parliamentary history provided more than the trappings; it was also fundamental to the legal logic, such as it was, of the Supreme Court’s judgment on the prorogation. 

Using the doctrine of the separation of powers, which, as I showed in the November issue, is itself artificial and without any constitutional foundation, the court declared that the crucial role of parliament (by which, equally unhistorically, it meant only the Commons) was “to hold the government to account”. Since prorogation prevented this, prorogation, save for a few days, was illegal. QED.

And by the way: since prorogation prevented parliament from “holding the government to account”, it couldn’t be a “proceeding in parliament” (though it took place in the Lords, the original parliament chamber) and so wasn’t protected by clause nine of the Bill of Rights against judicial scrutiny. QED again.

Even on its own terms, the transparency of this stuff is shocking. When the other side of parliamentary history is brought back into the picture, it is doubly so. For parliament as a facilitator of the Queen’s government needs, and has always needed, management.

And prorogation, in almost every century and under every stripe of government, has played a part in securing the passage of contentious but necessary legislation: from its use at Easter 1559 to force through the Elizabethan act of uniformity to its flagrant deployment by the Labour government in 1949 to amend the parliament act of 1911.

Boris Johnson’s government, in using prorogation, however cack-handedly, to try to get the Withdrawal Act through a recalcitrant Commons was thus doing no more than follow in the well-trodden steps of its predecessors. The constitutional outrage instead came from the bench of Supreme Court judges, whose ruling contrived to subvert precedent, history, the constitution and even elementary logic.

Johnson’s government has set itself the task of rebalancing the economy. At least as important is to rebalance the constitution. Speaker Hoyle has already begun to undo the worst effects of Bercow’s arrogance and vandalism.

The promised commission to examine the relationship between the executive, parliament and the judiciary needs to get to work fast also. A good start would be to teach their Supreme Lordships a little parliamentary history.