From the UK Supreme Court’s decision this morning in Miller it is quite clear that legislation is required to authorise the triggering of Article 50.
But what form should such legislation take? The majority decision does not give much explicit guidance. At para. 86, we are told that there must be “domestic sanction” in “appropriate statutory form”. At para. 122, there is a discussion that is apt to mislead (and seems to be misleading people already):
What form such legislation should take is entirely a matter for Parliament. But, in the light of a point made in oral argument, it is right to add that the fact that Parliament may decide to content itself with a very brief statute is nothing to the point. There is no equivalence between the constitutional importance of a statute, or any other document, and its length or complexity. A notice under article 50(2) could no doubt be very short indeed, but that would not undermine its momentous significance. The essential point is that, if, as we consider, what would otherwise be a prerogative act would result in a change in domestic law, the act can only lawfully be carried out with the sanction of primary legislation enacted by the Queen in Parliament.
Does this passage mean that “Parliament may decide to content itself with a very brief statute…”? I am not so sure. The point being made here, I think, is that passing legislation is a fundamental constitutional requirement in these circumstances (see especially the preceding comments in para. 121). The point made in oral argument that the majority is responding to is (I think) that legislation is not a meaningless formal requirement. Even if the legislation required turns out, on proper analysis, to be relatively brief it is nonetheless constitutionally vital to pass it. As a result, para. 122, in my view, is not best read as suggesting that a “very brief statute” will be sufficient. To know what is sufficient, it is necessary to read the majority judgment carefully.
First, there are two bases for decision in Miller: that triggering Article 50 will remove EU law as a source of law in the UK (see para. 62); and that triggering Article 50 will remove rights that are currently enjoyed by individuals in the UK (see paras. 70, 73). I accept that a brief bill making reference to s. 2 of the European Communities Act 1972 would be sufficient to cover the first basis for decision — or even a bill, as Jeff King has suggested, stating as follows “Notwithstanding the provision of any Act to the contrary, the Prime Minister shall have the authority to issue notice of the United Kingdom’s intent to withdraw from the European Union under article 50(2) of the Treaty of the European Union”.
But as I have occasionally suggested on Twitter in recent weeks (see also David Mead), I am not confident that a bill in such general terms would be sufficient to account for the rights that would inevitably be removed by withdrawal from the EU. If one of the problems with using the prerogative to trigger Article 50 is that it would inevitably deprive individuals of rights, it is difficult to see how a general statutory power would avoid the same problem. Common law courts are just as wary of broad statutory powers as they are of broad prerogative powers. It is striking that the majority relies on the principle of legality (see e.g. at para. 87), which could be invoked to read down a broad statutory power. It would certainly be safer, and perhaps more respectful of constitutional principle, for Parliament to set out the rights likely to be affected by the triggering of Article 50 and make clear that the executive is authorised to infringe those rights. One could imagine a clause saying, for instance “Notwithstanding any provisions of the X Act, the Y Act, the Z Act and other such Acts”.
As against this, there are indications that a bill in Professor King’s suggested terms would be sufficient: at para. 87, for instance (though this would seem to cover only the first basis of decision); and at para. 115, referring to “rights of institutional participation which are contingent” on EU membership (though this does not necessarily cover even part of the second basis of decision: see para. 73). More generally, it could plausibly be argued from the general context that Parliament would plainly intend to authorise the elimination of all such affected rights. In summary then, a one-line bill might be sufficient, but it would certainly be safer to make provision, insofar as this is possible, for those rights that would be eliminated by withdrawal from the EU.
Second, consider what the majority decision says about devolution. It is quite clear that whatever form the Article 50 authorisation bill takes, consent from Northern Ireland, Scotland and Wales will not be required (at paras. 136-151). But what about the content of the Article 50 authorisation bill? The following passage (at para. 132) is important, though it is difficult to decipher:
As already explained, it is normally impermissible for statutory rights to be removed by the exercise of prerogative powers in the international sphere. It would accordingly be incongruous if constraints imposed on the legislative competence of the devolved administrations by specific statutory provisions were to be removed, thereby enlarging that competence, other than by statute. A related incongruity arises by virtue of the fact that observance and implementation of EU obligations are a transferred matter and therefore the responsibility of the devolved administration in Northern Ireland. The removal of a responsibility imposed by Parliament by ministerial use of prerogative powers might also be considered a constitutional anomaly. In light of our conclusion that a statute is required to authorise the decision to withdraw from the European Union, and therefore the giving of Notice, it is not necessary to reach a definitive view on the first referred question [set out at para. 126]. The EU constraints and the provisions empowering the implementation of EU law are certainly consistent with our interpretation of the 1972 Act but we refrain from deciding whether they impose a discrete requirement for Parliamentary legislation (my emphasis).
On the one hand, it seems clear from the closing sentence that there is no obligation to include any reference to the devolution statutes in an Article 50 authorisation bill (even though a core feature of the statutes — an obligation of compliance with EU law — will be rendered nugatory by withdrawal from the EU). On the other hand, the other highlighted sentence suggests that, in line with my first point above, clear statutory authority might be required to permit the executive, by use of a statutory power, to empty provisions of the devolution statutes of meaningful content. Again, however, it might be thought that background context of an Article 50 authorisation bill would make it plain that Parliament’s intention in granting such a statutory power to the executive would be to permit just such a result.
There are doubtless other, more metaphysical issues that arise in connection with the wording of an Article 50 authorisation bill. This is a relatively hasty response, though I have been pondering it in recent weeks, so I welcome any comments you may have.