Not everyone is taking last week’s vote well. There have been calls for a second referendum or for Parliament simply to ignore the result. Whatever one thinks about the outcome of the referendum, these are not sensible suggestions, as I argue elsewhere. They are positively statesmanlike, however, by comparison to the proposal floated yesterday in the Guardian that Brexit would be unlawful and that the courts should be invited to say as much.

The referendum result does not of course itself withdraw Britain from the EU. But it does place considerable moral and political pressure on the government to act to withdraw Britain from the EU. The most obvious way to do so would by way of the process set out in Art 50, which begins when the member state (the UK) notifies the European Council of its intention to withdraw. Professor Philip Allott, a distinguished scholar and former FCO lawyer, argues that deciding to leave the EU and notifying the European Council would involve the exercise of legal powers. The government acts in question would thus be subject to judicial review and should be quashed if in excess of the limits on those powers.

It is by no means clear that deciding that the UK should leave the EU is an exercise of any power at all. It certainly does not change anyone’s legal relationship with anyone else. But notifying the European Council of the UK’s intention to leave would be an exercise of a public power, specifically the prerogative to conduct foreign policy and more specifically to advise the other 27 member states of the EU of the UK’s intention to withdraw.

Allott asserts that notifying the EU of the UK’s intentions is not an exercise of the prerogative, but rather of a power under EU law which forms part of our law by reason of the European Communities Act 1972. This is a strange analysis, the point of which seems to be to avoid the force of the traditional proposition that courts should be reluctant to review foreign policy, which is squarely a matter for the government. In this way, Allott implies, wrongly, that the courts would approach the UK’s notification of the European Council just as it would any other ordinary public action.

On what grounds might one challenge the legality of withdrawal? Allott outlines two grounds. He says, first, that the referendum was not called for the public interest but for the narrow interests of one political party (he refers to the Conservative Party manifesto). The courts will quash the corrupt exercise of public power and Allott gives as an example a planning decision made in favour of one’s friends. How is this remotely relevant to the referendum? He concedes that it would be “bold” to extrapolate from corruption in a planning case to national government and says his interest is not challenging the European Union Referendum Act 2015 itself, but rather the government action leading up to it.

This argument is hopeless. It alleges (obscurely) bad faith prior to the enactment of legislation that made the referendum possible and implies that this is a ground for quashing government action that takes place after the referendum itself. But it is impossible to challenge an Act of Parliament on the grounds of bad faith, including bad faith on the part of promoters of legislation; and the government’s introduction of a bill into the Houses of Parliament likewise cannot be challenged before a court. The assertion that the referendum was not in the public interest is open to argument but is not a point that can be put in question before a court of law. Parliament plainly thought holding the referendum was in the public interest when it enacted the 2015 Act and, one might add, a manifesto undertaking is nothing at all like bad faith or corruption. After the referendum has been held, government action to honour its outcome cannot possibly be blocked on the grounds that those who first proposed the referendum had improper motives.

The second ground is no better. Allott notes that the courts are willing to challenge the substance of a public decision on grounds that it exceeds the scope of the power. He concludes that the courts might well find any decision to withdraw from the EU to be unreasonable, disproportionate and arbitrary because it was based on the opinion of a bare majority of people in a referendum, the empowering legislation for which did not specify its legal effect. In deciding to withdraw from the EU on this basis, the government would be improperly ignoring the opinion of a very large minority and, Allott reminds us, governments are for the whole nation not some favoured constituency.

It should come as quite some surprise to the 33 million or so who voted last week to be told that it would be unreasonable, disproportionate and arbitrary for the government to honour the outcome of their vote. So too for the Parliament that enacted the 2015 Act, which was intended to make provision for the electorate to make a decision about whether the UK should remain part of the EU or leave the EU. The 2015 Act does not specify the legal effect of the referendum because it has no legal effect. But that is not to say it has or should have no effect as Allott implies. In respecting the referendum result and acting to withdraw the UK from the EU, the government will not be acting for a favoured constituency and ignoring the interests of the whole nation – it will be heeding the decision of the whole nation by way of the fair, lawful, public process Parliament deliberately chose.

Happily, there is no chance that these arguments will succeed. No British court will conclude that government action to withdraw from the EU on the basis of the referendum result is corrupt, biased or unreasonable. And no British court should do this: any such judgment would be an affront to democratic principle and to our constitutional order. This is not to say that litigation is unlikely: on the contrary, there is good reason to expect a legal challenge to government action to withdraw the UK from the EU. But when it comes the challenge will be more sophisticated than the argument discussed here and will aim to obstruct government implementation of the referendum result rather than to block Brexit altogether.

Professor Richard Ekins
Associate Professor, University of Oxford
Director of Policy Exchange’s Judicial Power Project