In widely reported remarks earlier this week, Lord Neuberger, the outgoing President of the Supreme Court, called for Parliament to tell our judges very clearly how rulings of the Court of Justice of the European Union (CJEU) are to be dealt with after Brexit. Lord Neuberger’s concern is to avoid judges being left without guidance, required simply to do as they see best, which might invite the unfair charge that they are choosing to make law, whereas in fact they would have been left with no alternative.

This concern to leave political questions to the political authorities, echoed in a recent speech by the outgoing Lord Chief Justice, Lord Thomas, is welcome. It runs contrary to a tendency otherwise evident in recent years, for courts (domestic and European) to be encouraged or required, or to choose for themselves, to transform political questions into legal questions.

So Lord Neuberger is right: Parliament should make very clear how our judges are to approach CJEU judgments after Brexit. However, the implication that the UK is on track to leave judges without guidance is dubious, and the present call for clarity risks becoming a hedge against later criticism, criticism that might well be justified if the courts misconstrue what Parliament decides.

The question is how our courts should deal with CJEU rulings after Brexit. There are two different types of ruling to consider: those made before exit day, and those made after. The European Union Withdrawal Bill provides for legal continuity, transposing relevant EU legislation and case law into domestic law as it stands on exit day. This is subject to various exceptions and will be open to be changed later by Parliament (of course) and ministers (in some cases).

For the courts, the Bill makes clear that initially nothing changes. They remain duty-bound to apply EU-derived law, until it is changed, including CJEU case law as at exit day. True, the Bill says that the Supreme Court is not bound by CJEU case law, but says also that in deciding whether to depart from that case law it must apply the same test as it does in relation to its own case law. The intention would seem clearly to be to maintain existing CJEU judgments, but leave it open to the Supreme Court to depart from them if the Justices think them clearly wrong and damaging. One might worry that it is not altogether clear when the Supreme Court will follow or depart from its own judgments, such that this test may be less robust than it at first appears.

If there is a problem here, it is the risk of leaving too much discretion to the Supreme Court. One solution might be to forbid the Court from departing from CJEU judgments at all. This would reserve to Parliament and to ministers (making secondary legislation) the decision of how or if to change EU-transposed law.

The main constitutional prize of leaving the EU is the restoration of effective legislative freedom. It is not the empowerment of domestic courts to make law. Leaving the EU legal order promises to help revive and maintain the traditional common law separation of legislation from adjudication. This is consistent with reserving to Parliament and ministers the main responsibility for deciding how to change EU-derived law, including how to correct CJEU errors in interpreting that law.

However, the focus of Lord Neuberger’s remarks was the status of CJEU rulings made after exit day. Here, the Bill says that the courts need not have regard to anything done by the CJEU (or other EU organs) but may do so if it considers it appropriate to do so. How should this direction be understood? Does it place domestic judges in an invidious position?

It would obviously be wrong to read this as in any way requiring domestic courts to follow post-Brexit CJEU rulings. If the courts chose to follow those rulings, treating them as authoritative in all but name, then they would have fundamentally misconstrued the legislation. The Bill permits courts to consider post-Brexit case law but permits them not to do so – the contrast with how CJEU rulings now operate (fully authoritative) and how pre-Brexit rulings are to operate (binding, subject to possible Supreme Court departure) is clear and striking.

There is another relevant contrast. The Human Rights Act requires domestic courts to take into account judgments of the European Court of Human Rights (ECtHR). In effect, this has meant that our judges consider themselves obliged to follow settled ECtHR case law, although British judges have shown willingness in some case to go beyond, or even to depart from, that case law.

Whatever the merits of the Human Rights Act, there are good reasons why our judges have had to consider very carefully ECtHR rulings, and in most cases have treated them as authoritative – the UK is a signatory to the ECHR and subject to the jurisdiction of the ECtHR. It would be very problematic indeed if our courts were to approach CJEU rulings after Brexit in a similar way, and there is no foundation in the text or structure of the Bill for such an approach.

The Bill does not permit courts to choose to treat future CJEU rulings as binding. It permits the courts to consider those rulings, dubious and otherwise, because they may well be very helpful. That is, those rulings might be persuasive, helping inform how our courts should understand EU-transposed law, law which is also being considered by another (foreign) court.

In other words, CJEU rulings might well prove helpful (or not) in the same way that decisions of the High Court of Australia or New Zealand Supreme Court are sometimes helpful, when considering common law rules or even legislation that exists (in one form or another) in related legal systems. This is the obvious way of understanding the Bill’s direction. Perhaps it can be stated more clearly still, but if the courts were to misunderstand it they would rightly be criticised.

The position may be different if the UK ends up agreeing to follow EU law (as understood by the CJEU) in this or that domain. But then the answer will be legislation, primary or secondary, specifying that the relevant rules are to be construed in light of the international agreement. (This would make the analogy with the ECtHR rulings stronger and the Human Rights Act a better exemplar.)

As matters stand, the UK is on track to depart from the EU legal order, choosing to maintain legal continuity at first, requiring our courts to uphold EU-transposed law until it is changed by Parliament or ministers, and permitting subsequent CJEU rulings to be considered if helpful. The details are important, and complicated, but the present alarm is not warranted.

Richard Ekins is Head of Policy Exchange Judicial Power Project and a Fellow of St John’s College, Oxford