Editors’ note: This is the first of a two-part contribution. The second part will be posted tomorrow.

The Brexit process continues to generate challenges for law, government and the constitution in the UK.  The ‘Joint Report from the Negotiators of the European Union and the United Kingdom Government on Progress During Phase 1 of Negotiations under Article 50 TEU on the United Kingdom’s Orderly Withdrawal from the European Union’ comes close to making an art form out of dodging or concealing many of these challenges on the initial withdrawal issues of citizens’ rights, the financial settlement, and perhaps especially, the border between Ireland and Northern Ireland. Yet given the Phase One Joint Report offers a masterclass in constructive ambiguities, in many respects it is surprisingly clear about some of the practicalities associated with the implementation in the UK of the Withdrawal Agreement.

In particular, the Phase One Joint Report contains a series of constitutionally contentious commitments made on behalf of the UK Government concerning the way in which domestic legal effect will be given to the post-Brexit rights of citizens contained in the Withdrawal Agreement. The Joint Report confirms that ‘UK domestic legislation will be enacted to this effect’ [34], and that citizens will be able ‘to rely directly on their rights’ as part of a framework which ensures ‘that inconsistent or incompatible rules and provisions will be disapplied’ [35]. This is all relatively familiar territory, in so far as EU law rights are presently given domestic effect through an Act of the UK Parliament (the European Communities Act 1972), and any national rules which violate those norms will be disapplied by the UK courts (s.2(4) ECA 1972, as applied following the decision of the House of Lords in Factortame (No. 2)). So the Joint Report, in this sense, is simply proposing to replicate – in broad terms – the present state of affairs relating to the status of EU law within the UK, and make this framework applicable to the rights which are to be incorporated from the Withdrawal Agreement.

Yet the Phase One Joint Report also goes further than the status quo in one key respect.  The specific legislation which is to be brought forward to deliver these commitments – the Withdrawal Agreement and Implementation Bill – will ‘fully incorporate’ the citizens’ rights provisions of the Withdrawal Agreement into UK law [36]. And, crucially, these fully incorporated rights will also benefit from an additional layer of legislative protection: the Joint Report states that ‘[o]nce this Bill has been adopted, the provisions of the citizens’ rights Part will have effect in primary legislation and will prevail over inconsistent or incompatible legislation, unless Parliament expressly repeals this Act in future’ [36].

Some may be initially underwhelmed by this form of legislative protection – after all, if the limitation is that Parliament could alter the incorporated Withdrawal Agreement rights simply by repealing expressly the planned domestic Bill, is that any protection at all? Viewed in UK constitutional context, however, this would actually constitute a quite significant example of a sovereign Parliament constraining its own power. For the doctrine of parliamentary sovereignty – the foundational principle of the UK constitution, which allocates to Parliament a law-making power which is legally unlimited – is a potential barrier to the constitutionalisation of the kind of legal commitments contained in the Phase One Joint Report. Perhaps ironically, the difficulty in giving legislative effect to such firm commitments is a potent example of inflexibility in the UK’s otherwise generally flexible constitutional order. And as a result, while a commitment that Withdrawal Agreement rights could only be removed by express repeal of the incorporating domestic legislation may seem insubstantial if considered in isolation, it is actually a comparatively robust form of legislative constraint in the UK context.

More fundamentally, however, it is also a matter for debate whether it is even constitutionally possible for Parliament to deliver on the UK Government’s comparatively robust commitment. This would go beyond the current framework through which EU law is given supremacy in the domestic legal system, in so far as the Phase One Joint Report seems to envisage the creation of an explicit legislative commitment protecting the Withdrawal Agreement and Implementation Bill from anything other than express repeal. To include such a commitment in legislation is arguably incompatible with the orthodox understanding of the doctrine of parliamentary sovereignty, according to which no Parliament can ‘bind its successors’, in order to preserve the continuing legislative freedom of future Parliaments over time. Indeed, on the traditional understanding of parliamentary sovereignty popularised by Dicey, the UK Government may be promising the ‘impossible’ (as, for example, is demonstrated in this initial reaction of Mikolaj Barczentewicz). To implement the Withdrawal Agreement in the way the Phase One Joint Report suggests may therefore lead us into potentially unprecedented constitutional territory – this challenge will be the focus of this two part blog post.

The Constitutional Possibility of ‘Express Repeal Requirements’

We should not, however, too quickly reach a conclusion that a legislative requirement of express repeal, such as that seemingly suggested in the Phase One Joint Report, would be constitutionally impermissible or unparalleled.

First, if we look beyond the Diceyan orthodoxy, there are other – and I would argue better – ways of understanding the doctrine of parliamentary sovereignty, according to which clauses of this kind, far from being problematic, become possible to reconcile with the idea of legally unlimited legislative power. The frequently repeated mantra that Parliament ‘can’t bind its successors’ is a trite and overinclusive claim about the potential uses of sovereignty, which can serve to limit Parliament’s legislative capacity – as a starting point, we need to ask more discriminating questions about what kinds of ‘binding’ may or may not be possible, and consider how different kind of legislative limits or conditions might impact on parliamentary sovereignty.

The ‘manner and form’ theory of legislative power, outlined by Jennings as part of a broader challenge to Dicey’s orthodoxy, provides an account of parliamentary sovereignty which permits the legislature to alter the future law-making process, recognising this to be a legitimate use of sovereign law-making power by distinguishing such change to procedural requirements from the (still impermissible) imposition of an absolute substantive limit on successor Parliaments. In principle, then, we can identify ways of understanding a potential ‘express repeal condition’ of the kind which might need to be contained in the Withdrawal Agreement and Implementation Bill which shows it to be both constitutionally permissible, and a manifestation, rather than a rejection, of the idea of parliamentary sovereignty.

‎Second, against this conceptual backdrop, we need to look at practice to determine whether this alternative understanding of parliamentary sovereignty provides a plausible interpretation of the contemporary power of the UK Parliament. While the Diceyan orthodoxy finds some support in the classic case law (most obviously the obiter dicta of Maugham LJ in Ellen Street Estates), a manner and form understanding of parliamentary sovereignty arguably underlies the decision of the House of Lords in Jackson, the leading modern authority on the legislative power of the UK Parliament. Yet more importantly, we can also trace a pattern of legislative activity providing varying examples of Parliament establishing in statute new procedural conditions which are integrated into the future legislative process for specific purposes. The series of ‘referendum locks’ established in the European Union Act 2011 (designed to limit further transfers of power or competence from the UK to the EU) is the most extensive example, yet we also see this approach now influencing the design of devolution legislation. The Scotland Act 2016 and Wales Act 2017 both introduce a legislative commitment to the continuation of the devolved institutions in each nation, making these legislatures and governments ‘permanent’, subject to abolition only if approved by the people of Scotland or Wales at a referendum. And this echoes the already established position in the Northern Ireland Act 1998, which provides that Northern Ireland shall remain part of the UK unless there is a majority vote to the contrary in a Northern Irish referendum.

Not only do we see Parliament enacting legislation containing such procedural conditions, we also see Parliament respecting these procedural conditions. While the most high profile clauses in the EU Act 2011 – the referendum locks – have never been engaged, this legislation also contained other procedural requirements to authorise certain kinds of decision-making at the EU level. And where the EU Act 2011 has required an Act of Parliament to authorise government action in this way, Parliament has both complied with that requirement, and stated the necessity of its compliance in express terms in the authorising statute. This sustained pattern is clear from the European Union (Approval of Treaty Amendment Decision) Act 2012, the European Union (Croatian Accession and Irish Protocol) Act 2013, the European Union (Approvals) Act 2013, the European Union (Approvals) Act 2014, the European Union (Finance) Act 2015, and the European Union (Approvals) Act 2015. We have even seen Parliament continue to respect these legislative conditions after the referendum decision to withdraw from the EU, in the European Union (Approvals) Act 2017.

This pattern of legislative activity is crucial if we are to take parliamentary sovereignty seriously – when considering the constitutional possibility of a statutory ‘express repeal requirement’, we need to give due weight to Parliament’s own understanding of how its sovereignty can be exercised, rather than privileging judicial accounts of the scope of legislative power. It is for this reason that it becomes problematic to analyse the status of a (potential) ‘express repeal requirement’ by questioning whether the Bill could be recognised by the courts as a ‘constitutional statute’, which the common law deems immune from implied repeal. This alternative approach to determining the possibility of Parliament delivering the legislative protection envisaged in the Phase One Joint Report will be challenged in part two of this post, which will conclude by reflecting on the (related) legal, political and constitutional implications of the UK Parliament enacting an ‘express repeal’ clause.

I am grateful to Adam Tucker for comments on a draft of this post.

Mike Gordon, Liverpool Law School, School of Law and Social Justice, University of Liverpool

(Suggested citation: M. Gordon, ‘Parliamentary Sovereignty and the Implementation of the EU Withdrawal Agreement (Part I)’, U.K. Const. L. Blog (17th Jan. 2018) (available at https://ukconstitutionallaw.org/))