The flaws with the government’s latest immigration bill are legion.  It almost certainly violates international law and the European Convention on Human Rights, which the government has freely admitted in refusing to state that the bill complies with the ECHR (an unprecedented refusal).  It is woefully impractical, requiring overwhelming structural investment in military barracks at a cost running into the billions. And it is pointless, with the bill doing nothing to actually stop asylum-seekers from reaching the UK via irregular routes, or to enable the government to return them to the countries they originally came from.

All of this has been said before.  Everyone knows that the asylum-seekers and migrants crowding on the shores of Calais have bigger worries than whether Suella Braverman has made a statement denying the applicability of the ECHR, and that people-smugglers are more motivated by profit than deterred by fear.  From here, it is easy, and perhaps correct, to assume that the legislation is not really intended to go anywhere.  It is nothing more than bait for the red-tops and an easy way of dividing the Conservatives from Labour ahead of the next general election.

But if we take the government at its word, and accept that this is a piece of legislation genuinely intended to solve the crisis, it may be that the outcome the government expects in the courts is not the one that it will get.  Judging from Suella Braverman’s comments before the House of Commons yesterday, she is fully aware that the legislation is incompatible with the UK’s international obligations.  Despite the ‘brightest legal minds’ in the country (one must pity James Eadie KC, the advocate the government often turns to, if he is trying to construct a legal defence for this) considering the question, no positive answer has been forthcoming.  Braverman has been left denying the legislation’s compatibility with rights in Parliament while doing the media rounds claiming its compatibility .

Under the everyday principle of parliamentary sovereignty, there is nothing that Parliament cannot legislate for.  Parliament may have chosen to enact the HRA and to have asked ministers to make a declaration that any future legislation is compatible with its requirements, but that does not mean that any future legislation must be compatible.   In much the same vein, when Parliament instructed the courts in s.3 HRA to interpret any legislation in a manner that is compatible with human rights ‘so far as it is possible to do so’, that did not mean that a future Parliament could not tell the courts not to use s.3 at all.

From here, it is easy to assume that the legislation will have a relatively easy ride through the courts.  The High Court or Court of Appeal may voice concerns, but the general arc of the Supreme Court’s jurisprudence over the last few years has favoured deference and has minimised international law.  The Supreme Court’s view might best be seen as that international law is nice to have, and that the government and Parliament should follow it, but that should they wish to depart from it, there is nothing the courts can do to stop them.  In instances such as this, it is for politicians and other people to intervene in defence of international rights.

What this assumption ignores, however, is the common law.  The common law and parliamentary sovereignty have a complicated history.  At its most simple, the common law is the decisions made by the courts.  Unlike the civil codes of the continent, which root almost every law in a promulgated document, drawing on their Roman heritage, the common law is found in the ether.  Courts hearing cases would look at the relationship and actions between the parties, and in making their decision would derive broader principles.  For instance, many of the foundational rules of contract law, like the need for a promise and an exchange, were not made by politicians, but by lawyers.

In matters like contract law, the relationship between Parliament and the common law is relatively straightforward.  If Parliament wants to change the rules of contract, or the rules of planning, it is free to do so.  But in questions of constitutional law, the issue is more complicated.  Constitutional law goes to the heart of government and the state, with relationship between the courts and the legislature in tension.  Some argue that the legislature, by virtue of its democratic legitimacy, supersedes the courts.  Others acknowledge that the courts pre-date the legislature, and suggest that the legislature is only supreme because the courts recognised it as such.

What is relatively uncontested though, is the idea that some values cannot be erased by Parliament, no matter how sovereign.  For instance, if Parliament was to legislate to abolish the judicial system, or to legalise slavery, many (although probably not all) would look to the courts to strike it down.  Equally, if Parliament was try to deny fundamental protections to some subset of society, like access to the courts, the courts could be expected to respond in two ways. Either by denying the legality of the legislative provision entirely, or (as is more likely) interpreting it in such a way so as to limit the effects of the provision.

It is one of these principles that is most intriguing within the government’s immigration bill.  Every lawyer worth hiring knows that the legislation raises questions of habeas corpus, one of society’s earliest and most fundamental of rights.  From the Latin, the phrase translates as ‘you may have the body’.  As a legal principle, it was originally used to challenge the right of the king to detain subjects without trial, forcing monarchs to release the detainee or charge them.  The bill does not try and dispute habeas corpus, or try to limit it.  Instead, it accepts that the principle still applies.  This puts the courts in the curious position where the more modern protections designed to protect refugees and asylum seekers are cordoned off, but the more ancient protections are still at hand.

Disregarding international law is one thing, but disregarding foundational democratic rights is quite another.  Despite the government’s acknowledgement of habeas corpus, this is what the illegal immigration bill does.  Inherent in the system proposed in the legislation is the refusal of access to the courts by those detained under its provisions.  It is almost impossible to reconcile this with claims of habeas corpus from those detained.

The question is what the government expects to happen as a result? It may be that they are thinking that the courts have been put in their box along with the common law, and that despite what Lord Toulson said in Kennedy, the common law has become an ossuary. Such optimism might not be naive given the court’s recent decision-making, but it may be futile.  Even Lord Reed has shown that when it comes to questions of the common law that go to unquestionably democratic fundamentals, he is unwilling to sit back and give the government free rein.  The modern slavery laws might not apply to refugees if this bill passes, but the more ancient ones still will.