UK Constitutional Law Association

affiliated to the International Association of Constitutional Law

Piet Eeckhout: The UK Decision to Withdraw from the EU: Parliament or Government?

Piet EeckhoutThe litigation concerning the triggering of Art 50 TEU is under way, with hearings this past week and early next.  It is the constitutional case of the century.  The Government’s skeleton argument has been published.  This reveals that one of the pillars of its defence is that the decision to withdraw from the EU has already been taken.  Consequently, all that is in issue is the authority to notify the EU of that decision, and to start the two-year period provided for in Art 50.  That, the Government’s case goes, is a decision of high policy which is rightly in the Government’s hands, and not in those of parliament.

In an excellent blog post, Mark Elliott and Alison Young dissect and critique this framing of the litigation.  They point out that it is difficult to identify who took the momentous Brexit decision, given that the referendum was advisory and there is no formal government decision either – only political statements.  Their critique is informed by UK constitutional authority.

In this blog I also want to focus on this question, but more from an external and EU law perspective.  The theses I want to present are twofold.  First, and at the expense of coming across as completely divorced from reality, I argue that there is as yet no Brexit decision.  Second, if the principle of UK parliamentary sovereignty is to continue to have real meaning, the decision has to be taken by Parliament, not the Government.

Ever since the debate about the respective roles of Parliament and Government in the Brexit process gathered steam, there has been an excessive focus on the notification question: is it for the Government to “trigger” Art 50 by notifying the EU, or is it for Parliament?  This kind of framing of the debate overlooks the wording of Art 50 TEU.  The first paragraph of that provision proclaims that “any Member State may decide to withdraw from the Union in accordance with its own constitutional requirements”.  The second paragraph states that “a Member State which decides to withdraw shall notify the European Council of its intention”.  So first, there must be a constitutionally orthodox decision to withdraw.  The notification is secondary.

The first paragraph of Art 50 distinguishes that provision from standard treaty clauses governing termination.  Those clauses usually conflate the withdrawal decision and its notification.  They reflect a traditional international law and international relations paradigm, according to which foreign affairs are mostly a matter for the executive.  The clauses themselves do not mention the executive, but they treat states as unitary actors, and the practice is simply that the state expresses itself internationally through executive action.  It is the government which acts on the international plane.  How such executive action comes about as a matter of domestic law is irrelevant, except in blatant cases (see e.g. Art 46 on provisions of internal law regarding competence to conclude treaties).  By contrast, Art 50 expressly requires that there is first an internal decision to withdraw, adopted in accordance with the Member State’s own constitutional requirements.  Once that decision has been taken, the Member State must notify, and I have no issues whatsoever with the position that this is properly governmental action.  Indeed, it is the European Council which needs to be notified, and that EU organ is itself composed of heads of state and government.  Nor would I argue that it is for any actor other than the Member State concerned to determine what its own constitutional requirements are, for taking the withdrawal decision.  The other Member States and the EU institutions do not, on the face of things, have the power to review whether the withdrawal decision is constitutionally orthodox.

And yet the reference to such a constitutionally orthodox decision is critical.  The EU is not a classical international organisation.  It establishes an ever closer union among the peoples of Europe (Art 1 TEU).  It is founded on representative democracy (Art 10 TEU), with both direct representation (in the European Parliament) and indirect representation (democratically accountable governments acting in the European Council and in the Council).  EU law directly confers rights on individuals (Van Gend en Loos).  These rights are extensive and meaningful, ranging from free movement, over trade, to fundamental rights in the EU Charter, including social rights, to a panoply of rights in EU legislation (consumer rights; environmental rights; rights to agricultural subsidies; company law rights; transport rights; rights to enforce foreign judgments; rights to asylum; etc etc).  As far back as 1974 Lord Denning likened the then EEC Treaty to an incoming tide, flowing into the estuaries and up the rivers, and said that it could not be held back because Parliament had decreed that it was part of UK law.  It is undeniable that the tide has waxed tremendously, but the point remains the same.  EU law is automatically part and parcel of UK law for as long as the UK is an EU Member State.  Or for as long as Parliament maintains the effect of EU law, through the European Communities Act 1972.

It cannot therefore come as a surprise that Art 50 requires that a decision to withdraw be taken in accordance with a Member State’s constitutional requirements.  Indeed, in a large majority of other EU Member States the constitution makes provision for EU membership, and withdrawal would require constitutional amendment.

Much of this EU law orthodoxy may not be to the liking of Brexiteers and Leave voters.  But if the UK chooses to withdraw in comformity with its international obligations, rather than through some type of revolutionary act, Art 50 must be taken seriously.  And these international obligations are not trivial, precisely because they have created all these rights, effectively for the whole of the populations of both the UK and of the other Member States.

So when the matter is looked at from an EU law perspective, there is a great legal question looming over Brexit: has the decision to withdraw been taken, and if so when and by whom?  I fully realise that even asking this question invites ridicule.  Politically, the Brexit decision is a fact.  But politics and law are distinct, and for good reason, as a core function of the law is to constrain politics in order to establish and safeguard liberal democracy.  And from a legal perspective, the difficulty of locating the Brexit decision needs little elaboration.  Parliament organised the referendum without spelling out its consequences, and it is generally accepted that the vote was merely advisory in the legal sense.  There is no formal Government decision to withdraw, nor has Parliament taken such a decision.  Just read the Government’s skeleton argument in the current litigation and Elliott and Young’s blog to see for yourself what intellectual contortions are required to argue that there is indeed a Brexit “decision”.

Why is this the case?  For the following reasons I would surmise.  The present Government does not want to recognise that the Brexit decision is for Parliament because it fears that the parliamentary debate may turn out to be uncontrollable, and lead to constraints on its margin of discretion in negotiations.  Besides, institutions usually claim that they have the power to do things themselves.  But nor is the government willing to adopt a formal Brexit decision, separate from its notification, because that would expose that decision’s lack of constitutional orthodoxy.  I do not claim great expertise in UK constitutional law.  But looked at from a distance, what is really left of the sovereignty of the UK parliament if a decision as seismic as that of withdrawing from the EU, a decision which entails the effective revocation of the European Communities Act 1972, this enormous estuary through which all these EU law rights flow into the UK, can be taken by the Government and does not require an “Act” of Parliament?  Of course, the people have voted.  But it is equally obvious that Parliament did not fully contract out the withdrawal decision.

I wish to state emphatically that I do not think that the UK Parliament should kick Brexit into reverse.  That would be an affront to the vote, and thus to democracy.  But there is a clear need for Parliament to get involved because the British people (and indeed those from other Member States affected by Brexit) deserve an open debate among democratically elected representatives about what Brexit means, and how best to organise the future relations between the UK and the EU.  And I think it would put the UK in a much better negotiating position if its proposals emanated from such democratic debate, rather than from mere cabinet meetings and Conservative party cenacles.

Piet Eeckhout is Professor of European Law and Vice-Dean of the Faculty of Laws, UCL.

(Suggested citation: P. Eeckhout, ‘The UK Decision to Withdraw from the EU: Parliament or Government?’, (15th Oct 2016) (available at

13 comments on “Piet Eeckhout: The UK Decision to Withdraw from the EU: Parliament or Government?

  1. Alan Robertson
    October 15, 2016

    I think your last paragraph is the nub of the whole issue. It would be better constitutionally if the decision was made by parliament but given the politics of parliament there is no guarantee that they would honour the vote. Individually the MPs could say well my particular electorate did not want to leave. Or they could set unrealistic and unachievable conditions on leaving which effectively stopped the process although they could claim not to be sabotaging Brexit. This would be easy to do as other than leaving the EU any other requirements are open to interpretation. The net result is that requiring the decision to be made by parliament could lead to a constitutional crisis.
    The solution is to allow the executive to trigger article 50 get the best terms they can. The actual terms do not matter so much politically because a) its not decided by us but by the EU b) the next parliament can seek to revise them if we are out of the EU and sovereign. The next parliaments will be free of the referendum result and free to do whatever they want with politics as normal.

  2. Steve Gwynne
    October 15, 2016

    Article 21.

    (3) The will of the people shall be the basis of the authority of government; this will shall be expressed in periodic and genuine elections which shall be by universal and equal suffrage and shall be held by secret vote or by equivalent free voting procedures.

    The Brexit campaign was built on the ideas
    1) Take back control in order that Britain become an independant sovereign nation which makes itsbown policy, laws and rules.
    2) Control immigration and consequently have border controls and a policy of immigration management.
    3) Not paying EU contributions
    4) To have the ability to stike free trade agreements independent of the EU.
    5) To leave the EU

    Basically these stated aims amount to a hard Brexit and as such the electorate were informed of the choice available albeit binary.

    EEA membership still means that 1-3 apply and all research has shown that the Brexit vote reflected a desire for 1 and 2 in particular. Therefore, a majority decision reflects a hard Brexit and not a soft one.

    Similarly constitutional arguments can be repudiated by the fact that the Labour Party (or any other party) can include in its next election manifesto EU or EEA membership and therefore allow the people to decide through normal electorate processes.

    Overall the referendum result reflects a majority leaning towards a hard Brexit and in terms of international human rights the will of the people is the basis of the authority of government, not the subjective wishes of a parliament who are neither representative of the EU referendum or the majority desire for a clean Brexit. At present Theresa May is reflecting both the referendum result and the majority desire for a clean Brexit and as such her actions are in accordance with popular sovereignty and international human rights.

    • Richard Allen
      October 16, 2016

      All very interesting but Parliament is sovereign. We had a civil war to determine that. We live in a representative Parliamentary democracy in which we appoint or remove MPs at elections and even though they represent us they are free to vote how they wish and we are free to remove them. A Representative Parliamentary democracy allows everyone to have representation through their MP. Thank God we do not live in the kind of nightmare binary yes/no democracy like the one you suggest.

  3. Malcolm Lidierth
    October 15, 2016

    What did Parliament believe the effect of a Leave vote would have when they passed the Referendum Act 2015? Activating A50 is the only way to start the process while complying with international obligations. So the binary referendum question, approved by Parliament, necessarily implies that A50 would be activated in the event of a Leave vote. By whom? Advice during the passage of the Bill was that the referendum outcome would “influence the Government in its policy decisions”. That advice was in the Briefing Paper from the Parliamentary Library (which comments from some MPs suggest was not read by all of them). There seems no obvious reason why Government policy should be considered at odds with the Parliamentary decision if the Government volunteers to accept the outcome of the referendum as binding, as it has.

    So there seems to be a case for arguing that Parliament has already granted the executive authority to trigger A50 through the Referendum Act. If so, Parliament has already contracted out “the withdrawal decision”, but not decisions about how that withdrawal will proceed i.e. A50(1) done, notification under A50(2) in hands of executive but everything else up for Parliamentary scrutiny.

    Many of the present arguments seem not to about whether Parliament did give the executive this authority but whether Parliament had the right to do so.

    The Referendum Act has created a constitutional void that courts are being asked to fill. We have perhaps the worst possible outcome: not the referendum decision, but the fact that those constitutional institutions which should be least politically partisan (the courts) being asked to fill a void full of politically contentious issues.

    It seems the people have little place in our constitution but their rights have. There is a right to protect existing rights, but fewer or no right to reject existing rights. Sir Humphrey would be having a field day, but would probably have drafted a clearer Referendum Bill in the first place.

    • Richard Allen
      October 16, 2016

      If you look at the 1975 referendum its very clear. It stated the Government would be obligated to follow the result ( ) Following the referendum there was then a free vote in Parliament with the Government voting in accordance with the referendum result as promised on the leaflet. If you read the 1975 Hansard debate ( ) you will see just how clear the process then was. Mrs Thatcher warns against referendums because they cause confusion if they are not clear and she was right. She also points out that a referendum can only be advisory and cannot bind parliament (although politically it will have that effect to a degree… MPs are free to vote as they wish but have to keep an eye on the electorate) but even so at least in 1975 they made the referendum clear because as you can see it states what will happen with the result. If you look at the leaflets for the Brexit referendum no mention is made of what will happen with the result. Neither is there anything on any Govt website or in the referendum act. In their fevered rush to push through Brexit the Brexiteeers failed to make the referendum clear and as a result it a total confused mess. I’m not sure what is scarier….the cock up with the referendum or the fact these idiots want to run the country.

    • Richard Allen
      October 16, 2016

      You don’t understand our constitution that’s the problem. At least Mrs Thatcher did. I suggest you read this

  4. Sean Feeney
    October 15, 2016

    The premiss for your argument, “given that the referendum was advisory”, is a central issue in the litigation.

    Your critique, like that of Elliott and Young, is uniformed by application of a potentially highly relevant House of Lords authority, Pepper v Hart [1993] AC 593.

    This authority which could provide the complete answer on the evidence of the clear statements by Government proposers (the substantive part of the ratio of Pepper) in Hansard proceedings (if admitted under the test in Pepper) for the Bill before Royal Assent, if it is justiciable (this is in issue), to the question you raise.

    See my first comment on Robert Craig’s Report of Proceedings post).

    Government proposers of the Bill made clear statements that the purpose of the Bill was to provide for a “decision”.

    It will become clear during oral argument if this is the defence to the claim.

  5. Richard Allen
    October 15, 2016

    So in layman’s terms its a buggers muddle in the finest British tradition.. …

  6. mark hardy
    October 16, 2016

    Everyone seems to be forgetting that The Queen’s Consent was neither sought nor given for either the 1975 or 2015 Referendum Bills.

    That is because the Office of Parliamentary Counsel must have advised that The Queen’s Prerogative/Estate/Asset would not be affected because the Referenda were to be advisory only.


    It was sought for the Scottish Referendum because it was intended to become immediately effective on a vote for independence and would impact the Duchy of Lancaster – as would have the EU referendum if it was intended to be a “decision”.

    Back to Parliament methinks.

    Technical knock-out? I think so, and am so arguing before the Court.

  7. Obiterj
    October 18, 2016

    Excellent article. I agree completely. No decision to leave has been taken since Parliament has not had its say. There are many additional factors which should be considered before a decision is actually made by Parliament and these include the fact that Brexit is likely to lead to the break up of the UK – (Scottish Independence / Unification of Ireland). Here is my view of 27th June –

  8. Pingback: Robert Craig: Miller: An Index of Reports and Commentary | UK Constitutional Law Association

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: