Parliamentary sovereignty is the bedrock of the constitution, and the courts ought to accept it, even when bad laws are passed. It is not the job of the courts to make the law, but to adjudicate on it. Thus the Appeal Court ruling against Shamima Begum is right, even if the decision of Sajid Javid, as Home Secretary, is wrong and ought never to have been made.

This is not because Ms Begum was groomed, trafficked and raped. These are serious considerations, and in all normal circumstances, a 15-year-old treated in such a barbarous way would not be held culpable for her actions. However, extenuating circumstances do not always excuse other crimes, and if they are serious enough, it is possible, although in my view improbable, that they outweigh this treatment of the accused.

Nonetheless, the decision to deprive Ms Begum of her citizenship is wrong because it attacks two linchpins of the constitution that safeguard us all. It is easy to defend constitutional principles in favour of good people, but it is more difficult to do so when it is acknowledged that someone has been involved with evil actions and organisations. Ms Begum, by her association with and strong support for Isis, falls into the second category, but the constitution ought not to be abandoned when it is inconvenient, because a fair process routinely benefits us all.

If in the process we forget the rule of law and make it arbitrary, then we do not defend our values but abandon them.

The first principle that is breached is the idea of equality of all British citizens before the law. The ability to deprive people, who have a claim to another citizenship, of their British passport, creates two categories of Briton. Those with no right to another nationality are in the first-class carriage. Whatever they do, they cannot be made an exile or outlaw and expelled from the country. On the other hand, those who themselves came to the UK or whose parents did so are in the second-class carriage. They may be stripped of their citizenship even if they have never claimed another foreign nationality or even visited the country. This is a fundamentally racist policy as it denies the absolute Britishness of all those who are either recent immigrants themselves or their children.

The concept of equality before the law is of great antiquity — Sir John Fortescue clearly understood it in his late 15th century writings — yet it has been dispensed with accidentally without a thorough debate, because of a dislike and fear of a small number of fanatics.

The other linchpin of the constitution that has been ignored is the right to trial by jury. This is easily dated to 1215 when it was guaranteed by the Magna Carta, coincidentally in the same year as Pope Innocent III banned trial by ordeal. Ms Begum has not been tried by a court or otherwise judged by 12 good men and true. Instead, a bureaucratic process has been adopted to strip her of her citizenship. This is not just: if she is guilty of a crime, then she ought to be tried and, if convicted, duly punished. It should not be done by the administrative act of a Secretary of State.

Isis was the epitome of evil, and its adherents deserve to be hunted down and prosecuted. Yet if in the process we forget the rule of law and make it arbitrary, then we do not defend our values but abandon them. Ms Begum may be the most well known, but she is not alone: twenty five other families, including some 40 children, are held in detention centres in North-East Syria. These are British families, subjects of the King.

Cecil Rhodes said that ‘to be born an Englishman is to win first prize in the lottery of life’. In my view, he was wrong. To be a Briton is the first prize in the lottery of life; it is not necessary to be born one. Each Briton is equal and there is no class between us. The person who took the oath today is as British as he whose ancestors were here before the Norman conquest. This is essential for equality and racial harmony.

The government ought to be the defender of all Britons at home or abroad, as Palmerston said, ‘so also a British subject, in whatever land he may be, shall feel confident that the watchful eye and the strong arm of England will protect him against injustice and wrong’. Instead, the Foreign Office sits on its hands when people like Jimmy Lai are shamefully treated by the Chinese government and the Home Office arbitrarily removes the citizenship of others. This weakens all our rights and undermines the constitution.