The all-party House of Lords Select Committee on the Constitution has published a devastating report on the United Kingdom Internal Market Bill. I recommend you download it and read it in full ahead of the House of Lords debate on Monday.

The bill, it says, “is presented as an economic measure to replace the EU single market arrangements at the end of the Brexit transition period”. But its effects go far wider. It is a bill of “great constitutional significance”.

Peers criticise the “unnecessarily heavy-handed approach” the bill takes to devolution. Like many commentators, though, I shall concentrate on the bill’s impact on the rule of law.

The principle that everyone from government ministers to the person on the street is bound by the law is a fundamental part of the UK constitution, the constitution committee says:

The rule of law also includes compliance with international law; treaty obligations are binding on nation states as a matter of international law once they are ratified.

The bill provides extraordinary delegated powers that the government acknowledged are for the purpose of breaking international law. Their use could place the UK in contravention of the withdrawal agreement and Northern Ireland protocol agreed with the European Union.

Setting out explicitly to break international law in this way is without precedent, the committee observes:

It jeopardises international obligations the UK recently ratified, undermines domestic law and is contrary to the rule of law. The government has not provided a satisfactory justification for this course of action and we do not consider that there can be one.

This constitutionally dangerous approach is compounded by the government seeking to put these powers beyond the reach of judicial oversight — a step that is also fundamentally at odds with the rule of law.

A government that disregards the rule of law cannot easily restore it. Any diminution of the rule of law is cause for serious concern. Society cannot afford to take this principle for granted or acquiesce in its violation.

The rule of law is essential to an open and democratic society and the institutions which embody and protect it. Any government that seeks to secure widespread compliance with the law must itself adhere to it.

Part 5 of the bill authorises breaches of the UK’s international law obligations under the Northern Ireland protocol and the withdrawal agreement, the committee says:

• Clauses 44 and 45 empower ministers to re-interpret and disapply parts of the Northern Ireland protocol, and to disregard their obligations under domestic and international law to enact the protocol.

• Clause 47 changes how the withdrawal agreement is given supremacy and direct effect under the European Union (Withdrawal) Act 2018. It seeks to restrict domestic judicial review of the exercise of powers granted in clauses 44 and 45.

On 8 September, the Northern Ireland secretary Barndon Lewis told MPs that the bill “does break international law in a very specific and limited way”. This, say peers, is a cause for serious constitutional concern.

Whether that breach is “specific and limited” or otherwise is irrelevant. Any breach of international law threatens to undermine the rule of law and international confidence in future treaty commitments made by the UK government.

As I have written in previous posts, the question of when the bill breaks international law is not clear. The committee agrees:

Whether the making of the bill by the UK government, as distinct from either its commencement or the introduction of regulations under clauses 44–45, amounts to a violation of the UK’s obligations to act in good faith remains an open question of public international law.

But peers have no doubt about its effect:

Notwithstanding the lord chancellor’s view that the powers were justified because there “could be a material breach by one of the parties” of their treaty obligations, as of now this would be incompatible with the UK’s international law obligations to act in good faith.

The committee had little time for a claim by Sir Stephen Laws QC, the former parliamentary draftsman, that there were “clear precedents” for this:

Whether or not the UK may have previously breached its obligations under international law does not justify further breaches of international law under the United Kingdom Internal Market Bill. It does not alter the rule of law implications of doing so.

The committee then referred to a statement published by the Cabinet Office on 10 September in which the government set out its legal position on the bill. It’s unusual for ministers to publish a legal opinion in this way but it must have had the support of the attorney general, Suella Braverman QC.

The statement said that “treaty obligations only become binding to the extent that they are enshrined in domestic legislation”. Peers disagreed:

It is misleading for the government’s official legal position to suggest that the dualist doctrine of UK domestic law means that treaty obligations become binding only once they are enshrined in domestic legislation. International law operates, and binds nation states, irrespective of domestic enactment.

The House of Lords European Union committee, which also published a report on the bill today, put it more bluntly:

The paper claimed that due to the UK’s dualist legal system “treaty obligations only become binding to the extent that they are enshrined in domestic legislation”. This last point is clearly wrong in law.

And the constitution committee was in no doubt about the consequences:

Any suggestion that the rule of law is not threatened by the bill because international law is of different legal standing to domestic law under the dualist doctrine is untenable. We agree with Lord Bingham that respect for the rule of law requires respect for international law…

Adherence to the rule of law is not negotiable. The government’s assurances do not alter the fact that the bill authorises conscious and deliberate breaches of the UK’s obligations under international law.

A government that brandishes the threat of breaching its international obligations, even in “specific and limited” circumstances, is one that undermines the rule of law.

Earlier this week, the lord chancellor Robert Buckland told the committee that the bill would not exclude judicial review of regulations made under it. I discussed Buckland’s reasoning in a piece sent to subscribers yesterday and predicted that peers would be “unconvinced by the lord chancellor’s answers”.

They say:

We are not persuaded by the lord chancellor’s construction of clause 47.

Clause 47 preserves, but also places significant limits on, the availability of judicial review. The statement in clause 47(1) that regulations made under clauses 44–45 “have effect notwithstanding any relevant international or domestic law with which they may be incompatible or inconsistent”, read with the broad definition of “relevant international or domestic law” in clause 47(8), would appear to prevent the courts from exercising their normal powers to declare regulations null and void in basic respects—such as if, for example, the regulations were lacking in legal certainty, or purported to create criminal offences without legal authority, or sought to impose retrospective penalties, or discriminated unreasonably. 

If enacted, such an exclusion of the judicial function would put ministerial regulation-making powers above the law in an unprecedented manner. It would be an unacceptable breach of the rule of law.

The rule of law requires that independent courts can adjudicate on the lawfulness of ministerial action. The effects of clause 47 are unclear and relate to a fundamental aspect of the rule of law.

The committee seemed equally unimpressed with the position taken by Braverman and her deputy, Michael Ellis QC:

The law officers play a crucial role in advising the government on the legality of its actions. Other ministers look to them, and to the lord chancellor, for guidance on the legal implications of the government’s actions. Parliament may look to them for legal clarification and reassurance.

It is essential that the law officers maintain the confidence not just of ministerial colleagues but of parliament and the public. We are concerned that, by endorsing a course of action with the United Kingdom Internal Market Bill which ministers have acknowledged will break international law and the UK’s treaty obligations, this confidence has been undermined.

The government’s first opportunity to respond to these devastating conclusions will come on Monday when two junior ministers, neither of them lawyers, will top and tail a debate on the bill at which more than 110 other peers are planning to speak.

It will not be a pretty sight.