It remains to be seen whether this bill will be passed, or in what form. At the time of writing, the draft text has not had its initial Commons debate yet.
Whether the legislation would "succeed" in any particular policy goal is hard to say. Part of its purpose is to be ostentatiously flourished for political reasons, whether or not it is ever applied in a courtroom. In the case of a specific person facing transfer to Rwanda, as we've seen in previous litigation, there are many possible grounds of challenge even aside from whether Rwanda is a safe destination. Those have included copious decision-making failures by the Home Office in the handling of individual cases.
The draft also allows a court to consider "compelling evidence relating specifically to the person’s particular individual circumstances" even as it purports to exclude the question of whether Rwanda is safe in general. In practice, this means that litigants would always attempt to put that material before the court. Even if it is not "compelling" or "particular", the court still has to look at it in order to make that determination, which would take time. It is also obvious that any litigation where the act is engaged would end up raising a host of serious constitutional issues, which would take time to resolve, further delaying any actual deportations. If the bill were to become law then it would still not "succeed" in enabling deportations for some time.
Below, I give an account of some the constitutional context, and a couple of examples to show how even the language in the bill might not be "enough" to make it do what the authors want.
Constitutional issues in general
The constitutional issues engaged, which are interrelated, include:
- Human rights; there are centuries of development around the idea that the government can't just do what it wants to you, now also reflected in various international treaties.
- Parliamentary sovereignty; its power to make whatever law it wants, and the consequent inability of the courts to deny that those things are law.
- International law; the UK's compliance with treaties it has signed, and with "peremptory norms" of customary international law.
- Powers of the courts; the strong presumption that governmental acts can be scrutinized, and that court orders will be obeyed.
I will begin as the bill does, with Parliamentary sovereignty. As classically expressed, Parliament can enact any law it wants. In the past, Parliament legislated that the bishop of Rochester's cook would be boiled alive (Act for Poisoning (1530), 22 Hen. 8 c. 9). In this view, any supposed limitations on Parliament's power, including various domestic legislation concerning human rights such as the Bill of Rights 1689, are just general expressions of the default legal situation and not actual constraints. This is often called a distinctively English view, since the historical Scottish understanding was different: there, Parliamentary activity was one source of law among many and subject to a wider moral and philosophical notion of justice. As Erskine put it, "all laws ought to be in themselves just [...] and human laws, when they prescribe any thing repugnant to natural justice, have no coercive force" (An Institute of the Law of Scotland (1773) at 1.1.3).
The modern way that this idea manifests is that the more Parliament is trying to do something apparently unjust or irregular, the more clear and explicit it has to be about its intent. The courts assume that Parliament legislates against a background principle of legality where its words are meant to be understood in the context of a system where we enjoy the rule of law. That means among other things that individual rights are to be protected, that state authorities act fairly and within their prescribed powers, and disputes can be resolved through fair procedures. A much-quoted statement by Lord Hoffmann puts it like this (R (Simms) v SSHD  UKHL 33):
Parliamentary sovereignty means that Parliament can, if it chooses, legislate contrary to fundamental principles of human rights. The Human Rights Act 1998 will not detract from this power. The constraints upon its exercise by Parliament are ultimately political, not legal. But the principle of legality means that Parliament must squarely confront what it is doing and accept the political cost. Fundamental rights cannot be overridden by general or ambiguous words. This is because there is too great a risk that the full implications of their unqualified meaning may have passed unnoticed in the democratic process. In the absence of express language or necessary implication to the contrary, the courts therefore presume that even the most general words were intended to be subject to the basic rights of the individual. In this way the courts of the United Kingdom, though acknowledging the sovereignty of Parliament, apply principles of constitutionality little different from those which exist in countries where the power of the legislature is expressly limited by a constitutional document.
Thus, while the Rwanda bill purports to do various surprising things, the fact that they are very constitutionally unusual means that the courts would need direct language in order to give them the effect that the bill's proponents want. While the "core" part of the bill - declaring that Rwanda is unconditionally safe - is pretty clear and direct in this way, other provisions are less obvious and leave open further avenues of challenge.
Determining a question of fact, such as the safety of Rwanda, is not inherently that abnormal. There are plenty of existing provisions of law that allow ministers to certify various facts to a court, such as who they should treat as the President of Venezuela. This particular one is unusually specific and contentious, but the basic idea is not novel.
In relation to international law, the UK operates a "dualist" scheme whereby treaties are not immediately effective as law in the domestic courts. There needs to be some action by Parliament to give them that effect. For example, even though the Refugee Convention of 1951 allows no derogation from the principle of "non-refoulement" (Articles 33 and 42), an Act of Parliament cannot be challenged just because it differs from what the UK signed in a treaty. But some important caveats include:
- When a treaty is implemented in an Act, the courts will refer to the treaty text and deliberations to understand what the Act means.
- They try to interpret treaties consistently with what other national and international courts have decided. That is because these things are agreements and they are meant to mean the same thing to all parties.
- Some international law is "customary" rather than codified. It can have effect as part of the common law.
For these reasons, the Rwanda bill tries to exclude certain international instruments from being taken into account in deportation decisions. That is because even though those may not have direct effect in the courts, the bill's sponsors still wanted to exclude other avenues for their application.
Example 1: Judicial review of ministerial compliance with ECtHR orders
The draft bill includes a clause 5(2) concerning interim measures from the European Court of Human Rights,
It is for a Minister of the Crown (and only a Minister of the Crown) to decide whether the United Kingdom will comply with the interim measure.
An "interim measure" is a kind of court order, one made during the course of proceedings rather than at the end. In England and Wales this would be called an "interim injunction" and in Scotland an "interlocutor". The point of this provision is that the bill preserves a possible route of appeal to the European Court, even though domestic courts are constrained. But the government would like to ignore a court order blocking somebody's deportation. Do the parenthesized words stop domestic courts from examining a Minister's decisions, and declaring them unlawful (or even issuing injunctions or contempt proceedings)? I think that this sub-clause is not enough to do that, because the backing constitutional assumptions are so strong.
The problems here are that court orders must be obeyed, that Ministers can be held to account if they fail to obey the law and that we are meant to follow treaties we have signed. The first two propositions are uncontroversial in relation to the domestic courts. See Craig v HMA  UKSC 6 at 46, "The Government's compliance with court orders, including declaratory orders, is one of the core principles of our constitution". It is also "fundamental to the rule of law that decisions and actions of the executive are, subject to necessary well established exceptions (such as declarations of war), and jealously scrutinised statutory exceptions, reviewable by the court at the suit of an interested citizen" (R (Evans) v AG  UKSC 21 at 52).
For the ECtHR, its authority in this arena derives from the UK's accession to the European Convention on Human Rights, which says in its Article 34 that:
The Court may receive applications from any person, non-governmental organisation or group of individuals claiming to be the victim of a violation by one of the High Contracting Parties of the rights set forth in the Convention or the Protocols thereto. The High Contracting Parties undertake not to hinder in any way the effective exercise of this right.
ECtHR case law, including Mamatkulov and Askarov v. Turkey (46827/99 and 46951/99), 2005 and Paladi v. Moldova (39806/05), 2009 is clear that non-compliance with interim measures can violate Article 34. These are not quite the same thing as a domestic court order and their status has been questioned. But while the bill includes language disapplying certain provisions of the Human Rights Act 1998 in several contexts, it leaves open the possibility of a domestic judicial review (which could result in a court order, which must be obeyed) of a ministerial non-compliance decision. In particular, section 6 of the HRA, which makes it unlawful for a public authority to act in a way which is incompatible with a Convention right, is not disapplied by section 3(5) of the bill in relation to a section 5(2) decision. (In the HRA, the right in Article 34 is not technically a "Convention right", but it's inseparable from those rights in the context of an alleged violation.)
Example 2: Non-refoulement as jus cogens
The recent Rwanda judgement in the Supreme Court, R (AAA) v SSHD  UKSC 42, deliberately did not address whether non-refoulement (that you don't send people back to place where they will be mistreated) is part of customary international law (para 25). It is certainly mentioned in all sorts of treaties but it might in addition be customary (the kind of thing you have to follow even if you haven't signed a treaty) or even a "peremptory norm" or "jus cogens" (the kind of thing, like genocide and torture, that is prohibited to the extent that any treaty allowing it is void).
The interaction between jus cogens and Parliamentary supremacy is uncharted. The Rwanda bill, in 2(5)(c)-(d), supposedly disapplies
(c) any other provision or rule of domestic law (including any common law), and
(d) any interpretation of international law by the court or tribunal.
This appears on its face to rule out a challenge based on the Rwanda treaty being unlawful (c.f. Article 53 of the Vienna Convention on the Law of Treaties) or on the non-refoulement principle being assimilated into domestic common law. However, the classic "maximalist" accounts of Parliamentary sovereignty predate the modern development of international human rights law. It is possible that in an outright conflict, even these direct words might not be enough. So far, the domestic legislation has always prevailed (see for example R (Bancoult) v SSFCA  UKHL 61) but it is no longer completely obvious that it always will.