The Rwanda Bill is making progress through Parliament, despite the judgement of the Supreme Court and a warning from the European Court of Human Rights.

The Bill aims to force UK courts and tribunals, in their decision-making capacities, to ‘conclusively treat the Republic of Rwanda as a safe country’ (s2(1)), in spite of the contrary evidence that led to the Supreme Court’s judgement in November last year.

Also included in the bill are sections that disapply many key provisions of the Human Rights Act 1998, and seriously limit access to judicial review of government actions.

Understandably, there has been public outcry from the Law Society, Parliamentary Committees, the ECtHR, and various political and legal commentators.

It’s somewhat bewildering that Parliament has such ease of power to ignore domestic and international law. Doesn’t it seem a bit strange that such constitutionally fundamental pieces of legislation can be passed in the same way as, say, the Electricity Transmission (Compensation) Act 2023?

So, despite the justified claims that the bill breaks the rule of law, or violates fundamental principles of human rights, the fact remains that if the bill passes through Parliament and receives royal assent, it will become law.

Most other countries require different law-making procedures depending on the scope of the law being proposed. Why, then, is there no difference in the procedures for passing constitutionally significant laws in the UK?

Parliamentary supremacy

The doctrine of parliamentary supremacy is a long-standing, fundamental pillar of the UK’s legal and political system.

Parliament is the supreme law-making body. No other institution is above the laws of Parliament, and the laws of Parliament apply indiscriminately. Further, there is no procedural difference in passing any kind of bill. Once debated and approved by both houses and receiving royal assent (which is entirely symbolic), it becomes law, regardless of its content.

Why is the UK still subject to this doctrine of absolute, unimpeded parliamentary supremacy?

People often point to The Case of Proclamations 1539, but the answer is not really that clear. In truth, the doctrine stems from a long history and is best thought of as something that developed as opposed to something that came into being at a particular time.

It has to do with a number of things: the origins of legislative power being held with the Crown, England’s exercise of power over Scotland, and the general philosophy of rights and liberties that developed throughout the last five hundred years, as well as other historical circumstances.

Part of this confusion, in fact, I reckon most of it, is due to the fact that there is no written constitution. If there was, you could point and say, ‘This is where parliamentary supremacy was established as the guiding principle of our constitution’. But the UK has no written constitution.

The unwritten constitution

The UK’s constitution is peculiar. There is no single document that the UK can refer to when trying to provide solutions to constitutional problems.

The constitution has developed over several hundreds of years, and its core components stem from a mixture of case law, legislation, convention, and academic scholarship. The Magna Carta established the right to a fair trial with a jury; case law from hundreds of years ago (see The Case of Prohibitions [1607]) established the principle that no one is above the law; and academic opinions (see A.V. Dicey) have solidified the separation of powers as a key aspect of the constitution.

This is peculiar because most other countries have a constitution written down. This is the core legal framework that cannot be changed or can only be changed through rigorous scrutiny by those who represent the electorate.

Take the US, for example, where the procedure of constitutional amendment is the only way to change the constitution, and that requires ratification by three-quarters of the state legislatures. Or Germany, where a bill changing the constitution must enjoy a two-thirds majority in both the Bundestag and the Bundesrat to become law.

As we have seen, the UK doesn’t have any such procedures in place. Why?

A fashionable argument for the lack of a written constitution in the UK is that there has never been a ‘constitutional moment’ in which codification was functionally or symbolically necessary.

The US had their moment of independence, the French had the revolution, and the Germans had the end of Nazism.

The UK can’t point to a sufficiently similar moment in its history, so perhaps that’s why there is no written UK constitution.

Informal checks and balances

As a result of the mixed bag that makes up the sources of the UK constitution, confusion arises.

As shown above, the reason why parliamentary supremacy persists in the UK can’t be pinned down, but it is still very often cited as the guiding principle of the UK’s system by senior judges, MPs, and academics.

Therefore, in theory, any law passed by Parliament in the ordinary way must be applied indiscriminately throughout the UK.

Although there is recognized evidence that certain checks and balances exist to limit this power.

For example, the courts have repeatedly said that they will not apply any legislation that directly contravenes the rule of law.

Also, there is the idea that Parliament’s power is limited by previous Acts of Parliament themselves, insofar as the'manner and form’ of Parliamentary procedures.

And lastly, the idea of international law having a direct effect on the member state. There are other examples of the informal system of checks and balances, like conventions, but the key takeaway is that they are informal.

Therefore, although these are each valid and exigent constraints on parliamentary supremacy, they are not of the same legal status as this doctrine. Parliamentary supremacy is often referred to as the ‘guiding principle’ of the UK constitution, and because there is no written constitution, there is no concrete answer to the debates that arise accordingly.

There are benefits to this unwritten approach. Organic growth, flexibility, adaptability, etc., are the oft quoted advantages of the unwritten approach to state management.

There is one glaring disadvantage, though, ambiguity.


Take the following example: Separation of powers is a key constitutional principle, and it states that no one branch of the state will exercise arbitrary power over the other. At the same time, so is parliamentary supremacy, which holds that any law passed by Parliament in the ordinary way is binding.

You can now see how there is tension between elements of the UK constitution. If Parliament is supreme, then is there any separation of powers?

The practical answer is, ‘Well, Parliament is supreme, but not entirely supreme, and there are a number of informal checks and balances that limit that supremacy’.

That works, but only most of the time.

Any constitutionally important issue is going to probe the limits of these informal checks and balances, and eventually an answer will be given, but not through a formal procedure accessible to all (i.e., one contained in a constitution); it will instead be a matter of ‘wait and see’.

The lack of clarity regarding the legal authority enjoyed by different branches of the state is what has led us to this confused situation, and clarity is what the UK now requires.

The Rwanda Bill has highlighted the dissatisfaction felt throughout the country with the current law-making process. It’s perfectly justified to be at odds with the idea that the Supreme Court can rule a government action unlawful, and then the government can push through legislation in a matter of months that changes the law accordingly.

The concept isn’t deplorable, but the means are. Changing laws to reflect modern views is a positive thing, but disregarding the nation’s highest court and fundamentally changing the constitution without any enhanced scrutiny just feels wrong.

A simple answer

The way to avoid this is to follow the example of most other states and codify the constitution. Enshrine certain constitutionally significant legislation and/or require the votes of increased majorities to pass laws that alter the constitution, or something like that.

To use a rough example, using the current situation as an illustration, one issue is that the Rwanda deportation plan is deemed unlawful by the Supreme Court. Perhaps you could codify the constitution to say ‘any bill that aims to overturn a judgment of the Supreme Court within the last five years must win a 2/3 majority vote in both houses’.

This doesn’t stop bills from passing. I’m not advocating for constitutional codification just to stop the passing of bills I don’t like.

Regardless of your opinions on the moral substance of the bill, it has exposed the procedural failings of the UK constitution. It’s not unreasonable, in a modern world so rapidly changing, to want clear and formal procedures for the passing of constitutionally significant laws, and these procedures should differ from the run-of-the-mill laws that pass every year.

Right now, the judiciary and the executive are at odds, the government is disregarding international law, and human rights abuses are likely to be committed by state agents by the close of the year, should the bill pass. And still, the doctrine of parliamentary supremacy holds its untouched neck, withered and wrinkled, above the other branches of state.

Does this not qualify as a ‘constitutional moment’?