In 2005 Tony Blair’s government passed the Constitutional Reform Act, which created the Supreme Court outside the House of Lords. The judiciary were alarmed by Blair’s high-handedness. Let’s just mention that illegal decision to wage war on Iraq, which arguably did more than anything to blow up the old constitution, with results we are now living through. At any rate the Constitutional Reform Act opens with these strange, defensive words: “This Act does not adversely affect… the existing constitutional principle of the rule of law.” By passing it, Parliament confirmed that the rule of law is a constitutional principle alongside that of its own sovereignty.

Now the rule of law is different from being truthful. And this is where things become interesting. Because tyranny exists when those exercising state power can lawfully decide for themselves what is true and what is false, and what is legitimate and what is not.

The lie becomes the truth

When the Johnson government decided to shut down Parliament for an unprecedented five-and-half weeks it claimed it did so because this was the normal thing to do when preparing a Queen’s Speech and it had nothing to do with Brexit or preventing the House of Commons from holding Johnson and company to account for their EU negotiations or lack of them. No one believes this claim. It is patently obvious that the motive was to shut down Parliament while Johnson and Cummings, or perhaps we should say Cummings and Johnson, decide what to do about Brexit.

As with Iraq, we are in the presence of a big lie that will have immense long-term consequences if the state can get away with it, as Blair did. So we are at an immensely important moment in the development of authoritarian rule. When everyone knows the government is being completely dishonest about the way it is ruling the country the legitimacy of the entire framework falls away.

When Johnson’s big lie was challenged in the courts few thought that the judges could find against the government. For while the government was acting in a way everyone agrees is politically disgraceful, it seemed the only remedy was an alternative politics: there was no way its behaviour was subject to judicial review.

But the keen-eyed lawyer and commentator David Allen Green noticed that no one from the government side had sworn an affidavit to say that the government’s account of its motives and reasons were true. It is one thing for the government’s lawyers to argue in court that what the government says it has done is lawful. It is something else for a minister or civil servant to tell a court that the government has indeed done what it claims. Because their statements will have to be made under oath. When this takes place truth is fused with law. For it is a crime, a serious crime, to perjure yourself.

Allen Green concluded that there must therefore be clear evidence that showed the government had not prorogued Parliament to prepare the Queen’s Speech in the normal fashion but had indeed done so to prevent the House of Commons from playing its lawful role over Brexit. Were such evidence to emerge at any time in the future, anyone who had lied to the court under oath would find themselves behind bars.

This led Dominic Grieve MP to put a motion to the Commons requiring named government employees, including Cummings, to publish all their communications about prorogation – which they are so far refusing to do. The obvious explanation for the government’s refusal to be open about its behaviour is that its deceit would be revealed.

It refused to tell even Cabinet ministers. After she resigned Amber Rudd told Andrew Marr that the Cabinet was not shown legal advice on Johnson’s decision to prorogue Parliament. “I asked for it,” she said. “And I was not given it. I was told that I would get it. But after persistently asking for it, I still haven’t got it when I resigned. I don’t think the Cabinet is having proper discussions about policy: the issue of prorogation we were told on the morning.”

Yesterday the Scottish Court of Session found that prorogation was unlawful “because it had the purpose of stymying Parliament”. This decision will go to the UK’s Supreme Court next Tuesday. Everyone expects the Supreme Court to conclude the opposite to the Scottish court and say that the silencing of Parliament can go ahead.

Oaths and old laws

It is suggested that the Scottish judges will in part base their full ruling, which is yet to be published, on the Scottish Claim of Right of 1689, which does not apply to England. Thus their judgement may reinforce the growing separation of the two main nations of the UK.

But England has its own Bill of Rights of 1689. This assumes that sovereign power is vested in the majority will of the two Houses of Parliament “fully and freely” representing the people. The Supreme Court could therefore find that any use by Crown or Executive of prerogative powers to interfere with the will of the two houses is an instance of what the bill describes as “arbitrary”’ power – just what the Bill of Rights states it is intended to outlaw.

There is another aspect to the scandal: the Privy Council. As its name suggests, this is a private group of advisers to the monarch. Technically the Cabinet is a sub-committee of the Privy Council. The council’s quorum is three and no notice of its meetings has to go to its members.

But even the Privy Council has rules, or at least one rule. This is set out in the oath which you take when you join. For a long time even this was secret. And for good reason, for among other things its states: “You will, in all things to be moved, treated, and debated in Council, faithfully and truly declare your Mind and Opinion, according to your Heart and Conscience; and will keep secret all Matters committed and revealed unto you, or that shall be treated of secretly in Council.”

What this means in plain English is that, when in council, members of the Privy Council must not only speak truthfully but are sworn to hold nothing back and must reveal their full views to the monarch (“faithfully and truly declare your Mind and Opinion”).

Of course this also means that members are not obliged to be truthful and honest when not in the monarch’s company, and indeed must also cover up what their fellow members say when in council. But let’s leave this on one side. For we can see that once more there is a fusion of lawful obligation and truthfulness – only this time lodged at the pinnacle of the British state.