Group portrait of the Seven Bishops whom James ordered imprisoned in the Tower of London in 1688, but who were acquitted of charges of seditious libel. National Portrait Gallery. Unknown artist. Public domain.

When David Davis, Secretary of State for Brexit, responded to the High Court’s decision that only parliament can trigger Article 50 he became unusually incoherent: “Parliament is sovereign, has been sovereign, but of course the people are sovereign”.

The issue might appear baffling and not only to readers around the world who are not British. The UK government exercises power in the name of the crown. The monarch's once absolute sovereignty is now commanded by Parliament in domestic matters. But abroad, the executive still retains an unchecked imperial absolutism, at least in theory. It can go to war or make peace using its royal preogative. The government claims that therefore it does not need Parliament's consent to trigger Article 50 of the Lisbon Treaty to start what it says must be the irrevocable process of leaving the EU; because it is a foreign treaty it has prerogative power. The High Court decided that on the contrary, as it also means undoing what is now domestic law, given the EU's regulation of people's rights, the government has to have parliament's agreement, or parliamentary sovereignty would be undermined. This is the decision the goverment has appealed and on which the Supreme Court will now decide.

The ‘sovereignty of parliament’ is a unique feature of Britain’s once durable, un-codified arrangements. These fashioned an immensely successful form of imperial government that dated back to the revolution of 1688. Monarchical absolutism, aristocratic privilege and capitalist energy combined into a new form of rule: cabinet government accountable to a parliament of Commons and Lords under the Crown. It created an engine of global conquest that was centralised yet flexible with built in checks that protected the Kingdom from both would-be dictators and, especially, democracy. No effort or skill was spared to ensure domestic consent. But this was, and was seen as being, the opposite of popular sovereignty or “government by the people”.

This is why the Brexit referendum is constitutional dynamite for Britain. The assumption was that it would confirm the status quo and that deference, self-interest and fear of the consequences, would renew consent to elite rule. Instead, consent was withdrawn. Instead, consent was withdrawn.

A new sovereign, ‘The people’, has now displaced the old. Unless 'the people' changes its mind, the Commons and Lords – both with Remain majorities - must obey and vote to leave the EU. It is no longer a matter of acting on the basis of their own judgment. By terminating the 1972 European Communities Act, 'parliamentary sovereignty' will only be restored as a technicality. For in fact and in spirit the referendum drove a stake through its heart. The 'Will of the People' must now prevail. Those who resist are 'Enemies of the People'.

This is the raw meat of dictatorship.

To protect us from it and ensure our rights, a democratic constitution is now essential; one that rests on popular sovereignty but protects the rights of all.

To achieve it we have to reawaken England’s passionate constitutional culture. From the Levellers to the Victorians the constitution was a matter of intense debate, concern and pride, a measure of the country’s self-belief. Coleridge even wrote a book about its essentially Christian nature.

Poets no longer refer to the constitution at all as something that stirs the passions of the self and public. In the twentieth century with the decline of Empire and the appropriation of self-belief by Fabianism, the culture withered. Today, to express an interest in the constitution runs the risk of being perceived as weird. So we have to start with first principles to establish why it matters to all of us and is not a lawyers’ plaything. A constitution sets out the rules for how a society’s rules are made or changed. 

In a sentence, a constitution sets out the rules for how a society’s rules are made or changed. Every country has one whether or not this is written down in one place, or many, or not at all. And all constitutions do three things.

First, they establish the authority that different centres of power have towards each other. Can the upper chamber frustrate the lower? What can local government do? This is where the famous separation of powers comes in, or, in the case of the UK, do not come in: between the executive (the government and civil service), the legislature (that makes laws but does not administer them), and the judiciary (which adjudicates what is lawful when this is disputed).

Second, all constitutions define the powers and rights of citizens, in our case, citizen-subjects. Do individuals have the right to vote, to assemble, to free speech, to property, to equal treatment? How are such rights protected? Can the executive imprison us or invade our liberty through surveillance without cause? If not, how must it establish due cause?

Third, all constitutions express the aspirations of their society: the direction they wish change to take. This might be to be non-racist (South Africa), to be Islamic (Iran), or to be liberal and not fascist (Germany) or universal (France). Aspiration need not be part of the main constitutional text, thus “Life, liberty and the pursuit of happiness”, the aspiration of the US constitution, is in the Declaration of Independence. Historically, England-Britain, as the firstborn nation, felt it had no need of vulgar aspiration when, after all – everyone else aspired to be like us. 

You can see immediately that because constitutions are about the way a whole society relates to itself they are living things. How a constitution is lived is always more important than what is written down. A constitution can be a defining, codified document; but the way a country defines its constitution is always more important than the way the constitution defines the country, as we can see in the United States today. (One of the measures of the collapse of a constitutional culture in the UK is the widespread belief that a written constitution means being like the United States, as if these are the only two alternatives in the world.)

When the then Prime Minister of the UK, David Cameron announced the referendum on 20 February he said, “The choice goes to the heart of the kind of country we want to be… You will decide”. This compressed together all three aspects of our constitution: how power is exercised, the rights of citizens, and our aspiration as a country. 

When Cameron did not get the desired answer the old order was submerged. The High Court decision is like the instruction King Canute addressed to the incoming tide. Not so fast, the judges said, the government cannot use the Royal Prerogative to overrule Parliament. This would undo everything since the seventeenth century that protects us from despotism. To which the government’s and, more important, the Daily Mail’s, reply is that it is the people’s prerogative that is now sovereign. 

Thersa May and the Mail are right. There is a new power in the land. The tide of the people’s determination cannot be reversed by a historic formula. Whatever the Supreme Court decides, an uncodified constitution offers no protection from ‘The Will of the People’ once this is unleashed. The danger of an intimidating populism is obvious and can even be given a name: Faragism. The danger of an intimidating populism is obvious and can even be given a name: Faragism.

The flexibility that was once the system’s greatest strength has folded. Its weakness has been evident ever since the UK joined Europe in 1972. Once, when he was head of the civil service and secretary to the Cabinet, Robin Butler was asked by a student “What is our constitution?” He replied, “It is something we make up as we go along”. Butler’s ‘we’ was not the ‘we’ of “We, the people”. He meant those like himself. Today, Butler’s establishment has been driven from power by an even narrower political-media caste. Now our constitution is something Rupert Murdoch and Paul Dacre make up as they go along.

A key to their success lay in the way Butler’s predecessors joined Europe. They were worse than deceitful in pretending it did not undermine the sovereignty of parliament. Britain became a member of the EU in bad faith: pretending that our continental partners’ far-reaching political-cultural project was for us only a matter of economics and instrumental advantage, which left our constitution intact. Yet it clearly put the UK, an uncodified multi-national entity, inside a larger multi-national entity set on codifying its reach. The nature of British rule could not but be threatened by such exposure.

The only way of staying in the EU in good faith was, and is, by becoming European. Britain needs its own written constitution, with a ‘constitutional patriotism’, proportional representation and a constitutional court capable (even if we leave) of testing the claims of the EU – to take three examples from Germany. (For how to create a constitutional convention see the debate edited by Stuart White)

This was the argument many of us made that influenced New Labour. We got our Human Rights Act, a Scottish parliament, a London Mayor, Freedom of Information and rid the Lords of most hereditary legislators. Together the reforms broke the informal checks and balances of the old regime while unleashing the national question. But Blair preserved its now unrestrained executive power, rather than be held to account by a new democratic settlement.

Worse, he replaced traditional concern for consent with public relations, which eventually degenerated into dodgy dossiers, while the embrace of market-fundamentalism treated the population as mere natives. The promise of New Labour was to restore trust in government: instead it was shattered. The promise of New Labour was to restore trust in government: instead it was shattered.

The referendum was a revolt of the natives, headed by a cynical media and Tories with roots stretching back to Enoch Powell. Victorious, their embrace of executive dictatorship is already more extreme than Blair’s, as in the name of the people they break resistance to Brexit and declare a final battle against the elitism of the old order. It may take a ten or twenty-year confrontation but the framework of 1688 cannot determine "the revolution” unleashed by Brexit.

Not least because Northern Ireland and above all Scotland have already started their own constitutional revolutions, which is why they felt safe enough to vote to stay in the EU. Now it is England’s turn.

The irony is that whether or not we leave the EU, by voting for Brexit we English now find ourselves in need of grownup, European-style arrangements. The outcome could be a federal UK, if Scotland agrees. That is for the future. What is clear is that England must bury its arbitrary, hyper-centralised empire-state to secure its once legendary tolerance. For even a newfangled supreme court cannot preserve the unwritten constitution being shredded by Brexit.

PS:  I have altered my mind after listening to the Court and some further reading. There are two ferocious lectures by Oxford academic legal specialists denouncing the High Court and insisting that the government can use the Royal Preogrative by John Finnis and Timothy Endicott. I had assumed that the High Court decision was so clear as to be irrefutable. But it seems possible that the Supreme Court could over-rule it on what to me would be technical grounds. If so, politically the government's defeat will be far greater than if it has to submit to pushing a short Bill though parliament. The idea that the country is 'taking back control' by having Theresa May do the job without consultation will turn the remain side into constitutional revolutionaries for sure, and we have the young on our side. The live stream of the Supreme Court in session is here, as well as helpful twitter streams: @faisalislam, @carlgardner, @joshuarozenberg - who has summaries for each half of the day.

Anthony Barnett is writing THE LURE OF GREATNESS: England's Brexit and Trump’s America, to be published by Unbound

This is a longer version of an article that was published in The Guardian, reproduced with thanks.