UK Constitutional Law Association

affiliated to the International Association of Constitutional Law

Mikolaj Barczentewicz: The Principle of Legality and the EU-withdrawal Statute

Mikolaj BarczentwiczLegal criticism of the EU (Notification of Withdrawal) Bill is quickly amassing. Notably, Paul Daly suggested that general phrasing of an authorisation to notify the UK’s intention to withdraw from the EU by the executive, of the sort contained in the Bill, may not suffice to ground lawfulness of such notification (or of withdrawing from the EU). It may not suffice, because the principle of legality could be said to require more specificity in conveying Parliament’s legislative choice to authorise withdrawal with all the possible detrimental consequences to individual rights. A similar argument was also presented in the “Three Knights Opinion” of Sir David Edward KCMG PC QC, Sir Francis Jacobs KCMG PC QC, Sir Jeremy Lever KCMG QC, Helen Mountfield QC and Gerry Facenna QC.

This view is unsound as it amounts to inviting the courts effectively to frustrate a legislative choice of Parliament. Parliament is capable, and should be so recognised by the courts, of making its choice to change the law known not only by express language of a statute, but also by implication. The context of enactment cannot be disregarded by the courts. The principle of legality stretched so far as to mandate interpretative literalism has no place in UK law. Furthermore, Parliament emphatically can legislate for an uncertain future when it cannot assess the precise effect of its legislative choice on individual rights.

I am setting aside the question of compatibility of the “Three Knights Opinion” with the Supreme Court’s decision in Miller, which Mark Elliott analysed in more detail. I also do not discuss the EU law side of the argument (see Joshua Rozenberg’s note).

Consider what would be required of the language of an authorising statute on the view I am arguing against. Paul Daly proposed, as an example: “Notwithstanding any provisions of the X Act, the Y Act, the Z Act and other such Acts”. However, if we assume the Daly and “Three Knights” view, then it is not clear how listing statutes would be qualitatively different from what clause 1(2) of the Bill already says (“This section has effect despite any provision made by or under the European Communities Act 1972 or any other enactment.”).

If the proposed text of clause 1(2) is not enough and if ‘Parliament must squarely confront’ (Lord Hoffmann in Simms at (131E)) detrimental effect on specific individual rights, then it seems that this view really calls for express recognition of this detrimental effect, regarding every such right. Imagine the task of spelling out all the individual rights that could possibly be removed or otherwise detrimentally affected by withdrawing from the EU! (Especially the ‘category (1)’ EU-originated rights, see Miller at [69]-[70]). It would turn Parliament’s legislative supremacy on its head for the courts to impose such a constraint on how Parliament can effectively express its legislative choice.

Even if the authors of the “Three Knights Opinion” would grant that a general clause (short of listing all the individual rights) would be sufficient, they have another bullet at the ready. They say (at [19]):

Until the terms of any withdrawal agreement and future relationship with the European Union are known, it is impossible for Parliament to know which rights will be lost or retained.

And then (at [20], emphasis added):

Only Parliament can give legal effect in the United Kingdom to any such agreement and it can do so expressly only when the parameters of that decision are known, in particular when it is clear which rights will be affected.

The boldness and novelty of the above statement is staggering. The “Three Knights Opinion” effectively introduces an idea of premature legislation as a constraint on Parliament’s legislative power. And they claim to do so in the name of Parliamentary Sovereignty!

On their view, given the uncertain effect of withdrawal negotiations, it is impossible for Parliament effectively to legislate now to provide both (1) a statutory authorisation of notification of intent to withdraw and (2) an authorisation of withdrawal. It is impossible because Parliament could not make its intent to allow for detrimental effect on individual rights express given that currently no one, including Parliament, knows which rights will be so affected.

The principle of legality taken this far has no place in UK law.

First, moving beyond interpretative literalism, the political context in which the future EU (Notification of Withdrawal) Act 2017 is likely to be enacted will frame the language of the statute with sufficient clarity so that any court should conclude that Parliament has provided, with full effect, both for (1) and for (2). It is more than plausible that Parliament’s intent will be to authorise withdrawal with all the consequences for individual rights, whatever they may be.

It will be a crucial part of the context of the future EU (NoW) Act 2017 that the Supreme Court made its decision in Miller accepting Lord Pannick’s ‘bullet’ argument. As Mark Elliott rightly points out, it is uncontroversial that in accordance with Miller, the future EU (NoW) Act will make giving notice under Article 50 lawful, with its consequences of changing domestic law in radical and fundamental ways. Notably, on the Miller view, the EU (NoW) Act is necessary because of the possibility of leaving the EU without an agreement due to the two-year deadline on negotiations under Article 50. In other words, Parliament is clearly authorising as much of an effect on domestic law (and individual rights) as would be the case on Brexit without a deal. Is it really so plausible to think that at the same time Parliament is not authorising less: a smaller effect on domestic law and individual rights, due to a withdrawal agreement?

Second, the kind of limitation on Parliament’s power to legislate suggested in the “Three Knights Opinion” does not exist in UK law. Even if, contrary to what I believe is the case, the current wording of the Bill, read in context, is not clear (or express) enough, it is open to Parliament to use general phrasing like ‘notwithstanding any effect on rights’ and ‘withdrawal from the European Union is authorised’. That we do not know what the exact effect of withdrawal on rights is going to be cannot preclude Parliament from legislating for uncertain future.

Mikołaj Barczentewicz (@MBarczentewicz), University College, University of Oxford

(Suggested cittion: M. Barczentewicz, ‘The Principle of Legality and the EU-withdrawal Statute’, U.K. Const. L. Blog (21st Feb 2017) (available at

4 comments on “Mikolaj Barczentewicz: The Principle of Legality and the EU-withdrawal Statute

  1. Sean Feeney
    February 21, 2017

    One does not need to be Sancha Panza to see that the Three Knights’ opinion tilts at two very wrong windmills.

    It is currently highly unlikely that this majority Government pursuing its manifesto commitment to implement the referendum result will either change its consequent policy that that the UK will exit the EU without a negotiated agreement, if satisfactory terms cannot be negotiated, or give a conditional notice.

    The most likely future legal challenge (unless the Bill is substantially amended), given uncertainty is the essence of the Article 50 withdrawal process, is that Parliament has simply conferred a wide-ranging discretionary power of notification which cannot lawfully be exercised until Parliament has authorised a “decision to withdraw from the European Union”.

    See the clarification of the majority’s “conclusion” in Miller curiously buried in an introductory clause in a passage on devolution issues at [132]:

    “In light of our conclusion that a statute is required to authorise the decision to withdraw from the European Union, and therefore the giving of Notice, …”.

  2. Ed Argles
    February 21, 2017

    I wonder if it’s possible to go further and argue that the principe of legality found in Miller–where the contextual and constitutional significance of the ECA 1972 meant it had effect beyond the merely procedural quality of its provisions—would grant the EU(NoW)A 2017 far-reaching implied effect.

  3. Kevin Clarke
    August 17, 2018

    Interesting article. As a layman I struggle to follow all the points. Does your view evolve in light of recent events? We now have a fixed but moveable exit day, some form of commitment to Parliamentary approval and a commitment in law to avoid border infrastructure on the UK/EU land border.

  4. Kevin Clarke
    October 17, 2018

    I’m not sure about the argument that every right must be listed. In Miller it was noted the length of a statute was not a measure of its importance. The Notification Act of course was famously short. What is required is that Parliament is clear in its intent.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Ordinary membership

UKCLA yearly membership (ordinary)


Student membership

UKCLA yearly membership (student)


Associate membership

UKCLA yearly membership (associate)


%d bloggers like this: