Since writing this post, I have finished work on a co-authored article examining the European Union (Withdrawal) Act 2018 and analysing its constitutional implications: Mark Elliott & Stephen Tierney, ‘Political Pragmatism and Constitutional Principle: The European Union (Withdrawal) Act 2018’. A pre-publication version of the article (which will be published in the journal Public Law) can be downloaded here

After over 270 hours of parliamentary consideration,1 the European Union (Withdrawal) Act 2018 became law on 26 June 2018. One of the most constitutionally significant pieces of legislation to have been enacted in recent memory, it paves the way for the UK’s departure from the EU and will form the legal foundation of a substantial amount of domestic law post-Brexit. While the UK has been an EU Member State, a good deal of its law has derived from the EU. After Brexit, the UK will be free (subject to the terms of any agreements with the EU) to go its own way, making new domestic legislation that differs from EU law. But the sheer volume of EU law means there is no prospect of its being replaced with new UK legislation by 29 March 2019 — ‘exit day’. To avoid an enormous legal black hole from arising, the Withdrawal Act will take a snapshot of EU law as it exists immediately before Brexit, converting it into domestic law: a huge, and imperative, exercise in legislative copying and pasting (and then, as we will see in a moment, editing).

Copy and paste: ‘Retained EU law’

The Act creates a new category of domestic law: ‘retained EU law’. This takes a number of forms. ‘EU-derived domestic legislation’ is existing UK law that relates to EU law (e.g. legislation enacted to give effect to EU directives). Much of that domestic law was made by UK Ministers using powers given to them by the European Communities Act 1972. That Act will be repealed as soon as Brexit occurs,2 but the Withdrawal Act will ensure that laws made under the 1972 Act remain valid.3

A different issue arises in relation to EU law that has direct effect. Such law automatically has effect in the UK while it is a Member State. To ensure that such law does not simply evaporate on exit day, the Act converts directly effective EU law into UK law. Thus, for instance, EU regulations which have direct effect will be turned into a new type of domestic law to be known as ‘retained direct EU legislation’.4 Other directly effective EU law, such as relevant provisions of the EU Treaties, is also transformed by the Act into domestic law.5

And then edit: Dealing with ‘deficiencies’

All of this is sensible in the interests of legal continuity. But absolute continuity is neither desirable nor feasible. A good deal of EU law that currently applies in the UK is predicated upon its being a Member State: such law will simply not make sense following Brexit. The Act therefore gives Ministers time-limited powers to amend domestic law (including, but not only, retained EU law) to address ‘deficiencies’ arising from Brexit; this extends, subject to certain exceptions, to allowing Ministers to do anything that could be done by Act of Parliament.6

In the circumstances, ministerial amendment powers are imperative: it would be impossible for Parliament to enact legislation making all the necessary changes in time for Brexit. But the breadth of the powers proved controversial during the Act’s passage through Parliament. The Government saw off an attempt to make the powers exercisable only when their use is ‘necessary’, but did concede some points: thus, they cannot be used to create new public bodies or to amend the Act itself. Scrutiny of these powers’ use was also strengthened during the Act’s passage, including through the creation of a triage process.7 Parliamentary ‘sifting committees’ will thus be able to recommend closer scrutiny of proposed ministerial amendments where they feel this is warranted, albeit that Ministers will be able to override such recommendations.

Retained EU law’s legal status

One question that was raised (in particular by the House of Lords Constitution Committee)8 during the Act’s passage through Parliament concerned the legal status of retained EU law. In particular, is it to be treated as if it were primary legislation (i.e. an Act of Parliament) or delegated legislation? The final version of the Act is a little clearer than the original Bill. It now explicitly provides that pre-Brexit EU-related domestic legislation maintains its original status:9 so, for instance, delegated legislation made under the European Communities Act 1972 will remain delegated legislation. In contrast, retained direct EU legislation — i.e. EU regulations that have been converted into domestic law — is not generally10 assigned any particular domestic status. It will thus defy conventional taxonomy, being neither primary nor secondary legislation.

The Act does however create a new taxonomy, distinguishing between ‘minor’ and ‘principal’ species of retained direct EU legislation.11 This will, for instance, enable Parliament when legislating in the future to ensure (should it so wish) that ministerial powers to amend ‘principal’ retained direct EU legislation are more limited or subject to greater parliamentary scrutiny. The Act also provides that, post-Brexit, the principle of the supremacy of EU law continues to bite upon pre-Brexit domestic law.12 The intention appears to be that at least some13 retained EU law will prevail over (other) pre-Brexit domestic legislation. This creates a conceptual conundrum — how can the principle of the supremacy of EU law meaningfully apply when Brexit rids the UK of all EU (as distinct from EU-derived) law? — that goes unaddressed by the Act, and which the courts will doubtless have to resolve.

The territorial constitution

The Act also has important implications for the UK’s territorial constitution. The original version of the Bill put all retained EU law off-limits to devolved law-makers, subject to the possibility of the UK Government’s gradually devolving authority to alter retained EU law. This was intended to ensure that important pan-UK arrangements — such as the UK’s internal single market — that are currently vouchsafed by EU law would not be compromised by Brexit. However, following allegations that this amounted to a ‘power-grab’ by the UK at the devolved institutions’ expense — because it would have diverted to London powers that would otherwise have flowed from the EU to the devolved capitals upon Brexit — the Bill was amended.

The Act now prevents devolved institutions from amending retained EU law only in ways that are proscribed by regulations made by UK Ministers.14 Before such regulations are made, devolved legislatures must be consulted, but ultimately they cannot block UK Ministers from limiting their powers over retained EU law. The upshot is that the Act still enables the UK Government unilaterally to limit devolved powers in this area. The Scottish Parliament took such exception to this regime that it refused to grant its consent to the relevant part of the Withdrawal Act.

What about a transitional period?

The Withdrawal Act, originally passed by Parliament, does not accommodate the sort of transitional — or ‘implementation’ — period that the UK Government is attempting to negotiate with the EU. Under such an agreement, the key effects of the Withdrawal Act would, in practice, be deferred to the end of the proposed 21-month transitional period, i.e. until the end of December 2020. The Withdrawal Act, as described above, would then swing into action, capturing EU law and turning it into UK law. During the transitional period, however, EU law itself — including any new pieces of EU law — would continue to apply in the UK. These modifications to the Withdrawal Act will be made by the proposed European Union (Withdrawal Agreement) Bill.

Final thoughts

The EU (Withdrawal) Act 2018 is a legally complex piece of legislation that engages an interlocking set of constitutional issues. The extensive authority transferred by Parliament to Ministers to amend the statute book shows just how flexible the UK constitution is and raises serious questions about the separation of powers (even though ministerial authority under the Act is somewhat more circumscribed than in the original Bill).

The Act also raises broader questions about the relationship between the executive and Parliament. A particular irony is that while those who favour Brexit tend to frame it in terms of restoring parliamentary sovereignty, they also tended to oppose attempts to enhance Parliament’s role in the Brexit process. Thus, while the Act does now provide that the Government cannot ratify any withdrawal agreement unless Parliament approves, this arguably falls short of a truly ‘meaningful vote’ that would enable Parliament to shape the terms of Brexit.15 (Parliament missed a golden opportunity to shape those terms — and to ‘take back control’ — when it gave the Prime Minister unfettered power to trigger the withdrawal process in 2017.)16

Finally, the Act places the UK’s fragile territorial constitution in sharp relief. It is highly significant that the UK Parliament went ahead and enacted the Withdrawal Act in spite of the Scottish Parliament’s refusal to consent to it. While such consent is not legally necessary, it is required as a matter of constitutional convention — a convention which the Westminster Parliament has itself recently legislatively endorsed,17 albeit that it stopped short of giving it the force of law.18 Westminster’s preparedness to press ahead against the Scottish Parliament’s wishes may be a graphic illustration of the former’s sovereignty. However, like so much connected with Brexit, the longer term implications of such bullishness — in this case, for the stability and integrity of the United Kingdom itself — remain to be seen.

I am grateful to Stephen Tierney, Professor of Constitutional Theory at the University of Edinburgh, and Jack Williams, a barrister at Monckton Chambers, for their comments on an earlier draft of this post. The usual disclaimer applies.


1  Institute for Government, ‘EU Withdrawal Bill: amendments and debates’.
2  EU (Withdrawal) Act 2018, section 1.
3  EU (Withdrawal) Act 2018, section 2.
4  EU (Withdrawal) Act 2018, section 3.
5  EU (Withdrawal) Act 2018, section 4.
6  EU (Withdrawal) Act 2018, section 8.
7  EU (Withdrawal) Act 2018, schedule 7, paragraph 3.
8  House of Lords Constitution Committee, ‘European Union (Withdrawal) Bill’ (9threport, 2017–19 session).
9  EU (Withdrawal) Act 2018, section 7(1).
10  There is an exception. For the purposes of the Human Rights Act 1998, ‘principal’ retained direct EU legislation is to be treated as if it were domestic primary legislation, while ‘minor’ retained direct EU legislation is generally to be treated as if it were domestic secondary legislation: EU (Withdrawal) Act 2018, schedule 8, paragraph 30. On the distinction between ‘principal’ and ‘minor’ retained direct EU legislation, see n 11 below.
11  EU (Withdrawal) Act 2018, section 7. The ‘principal’ category includes retained EU law that derives from EU regulations; into the ‘minor’ category falls retained EU law that derives from inferior forms of EU legislation (e.g. EU tertiary legislation).
12  EU (Withdrawal) Act 2018, section 5(2).
13  The Act is not clear as to which forms of retained EU law the supremacy principle continues to apply to, although the intention is presumably that it should apply to retained EU law corresponding to forms of EU law, such as directly effective regulations and Treaty provisions, that themselves had supremacy.
14  EU (Withdrawal) Act 2018, section 12.
15  EU (Withdrawal) Act 2018, section 13.
16  European Union (Notification of Withdrawal) Act 2017.
17  See, in relation to Scotland, the Scotland Act 1998, section 28(8) (as inserted by the Scotland Act 2016, section 2).
18  See the Supreme Court’s judgment in R (Miller) v Secretary of State for Exiting the European Union [2017] UKSC 5.