UK Constitutional Law Association

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Colm O’Cinneide: Why Parliamentary Approval for the Triggering of Article 50 TEU Should Be Required as a Matter of Constitutional Principle

Colm O'CinneideThe argument that Article 50 of the Treaty on European Union (TEU) cannot be lawfully triggered without the consent of Parliament has generated plenty of excited discussion over the last week, both in specialist legal circles and in the wider world. The announcement by Mishcon de Reya that that legal action was pending to ‘ensure the UK Government will not trigger the procedure for withdrawal from the EU without an Act of Parliament’ has brought this debate to boiling point. Some commentators have talked excitedly about a ‘legal dream team… launching a last gasp legal bid to preserve Britain’s European Union membership’. In response, there has been a visceral backlash in pro-Leave ranks against what they see as an attempt by conniving lawyers to thwart the will of the people. The front page of the Daily Express on 4 July 2016 led with the banner headline ’Top Lawyers in Threat to Referendum Vote & Democracy’, going on to warn about ‘outrage and rioting on the streets’. Similarly, Professor Frank Furedi commenting on Twitter described the proposed legal action as nothing less than an ‘authoritarian attempt at a “legal” coup’, with Brendan O’Neill indulging in similar hysteria in the Spectator.

The response from the government has been more measured, but thus far less than encouraging for those advocating a parliamentary vote on Article 50. Giving evidence before the Commons Foreign Affairs Committee on 5 July 2016, Oliver Letwin MP indicated that he had been advised by government lawyers that Article 50 can be invoked under prerogative powers, and thus no parliamentary vote would be required to initiate that stage of Brexit. As a result, the legal debate about whether Parliament must approve the triggering of Article 50 is set to run and run – and looks likely to result in litigation.

However, this obsessive focus on the question of whether Parliament must approve a decision to trigger Article 50 risks obscuring the fact that good reasons exist – both prudential and principled – as to why government might want to seek the approval of Parliament before taking this step irrespective of whether it is required by law. Governments have previously sought parliamentary approval for the exercise of prerogative or statutory powers: examples include not only the authorisation to invade Iraq in 2003, but also the way in which the coalition government sought parliamentary approval in 2013 for exercising the UK’s right under the Lisbon Treaty to opt-out of a range of EU police and criminal justice measures. A similar approach may be warranted here – and the tunnel vision engendered by legal conflict should not blind government to this possibility.

The prudential case as to why the government should announce it will be seeking Parliamentary approval before Article 50 is triggered can be outlined in brief. It could reinforce the negotiating position of the UK Government in Brexit talks, by insulating it against any pressure brought to bear by EU institutions or other European states for it to accelerate the Article 50 process. Furthermore, involving Parliament would help to share the burden of responsibility – and by extension to spread the blame if the Article 50 process goes awry.

But there also exist compelling reasons of constitutional principle as to why Parliament should approve any invocation of Article 50. As the institution that is supposed to serve as the representative voice of the people, Parliament is given a central role in the UK constitutional order. It would be compatible with its sovereign status for it to have the final say as to whether and when the Article 50 trigger is pulled – and, by extension, it would enhance the democratic legitimacy of this decision.

Invoking Article 50 is not going to be a normal, run-of-the-mill exercise in international diplomacy. As Barber, Hickman and King have noted in an earlier and by now widely-cited post on this blog, the triggering of Article 50 will have momentous consequences for the UK. It will also set in motion a negotiation process in which the UK will be at a disadvantage because of the (difficult to reset) two-year countdown to exit. The question of when this process should be commenced has already become a matter of serious political debate. There is some support for a rapid triggering of Article 50 from different elements of the political spectrum: others fear that a precipitate rush to invoke Article 50 will accentuate the negative consequences of Brexit. The importance of this process, and in particular of the timing issue, suggests that Parliament should have the final say as to when and if it is triggered.

Furthermore, the UK government will presumably need to have a negotiation strategy in place before invoking Article 50. This will require choices to be made as to what type of relationship it wishes to establish going forward with the EU post-Brexit, and what public policy goals might have to be sacrificed or watered down to bring that relationship into being. These choices are likely to be controversial: for example, a decision by the government to prioritise retaining access to the European single market may attract criticism from elements of the Leave campaign who might see this emphasis as inevitably opening the door to compromise on the free movement issue. As a result, a good case can be made that Parliament should have the opportunity to debate the contents of any such strategy before Article 50 is triggered. If, on the other hand, Parliament only gets to debate and accept/reject the outcome of the strategy at the end of the negotiating period, then this risks creating a situation where Parliament is presented with a fait accompli and given a binary choice to accept or reject the deal on offer with the clock ticking.

Some pro-Leave commentators have suggested that the referendum result has settled the matter, and that no further democratic input in the form of a parliamentary vote is required before Article 50 is triggered. For example, Martin Howe QC, the Chair of Lawyers for Britain, a pro-Leave legal campaigning group, has argued that ‘the decision of the British people in a national referendum authorised by Act of Parliament not merely permits but mandates the giving of notice [under Article 50], without the need for any vote by Parliament’.

There are two problems with this argument. First of all, the advisory character of the referendum complicates the picture: it was called to guide Parliament, not to bind the hands of government. Secondly, it glosses over the primacy assigned to representative governance conducted through Parliament within the UK’s constitutional order. It is highly probable that Parliament, if asked to approve a triggering of Article 50, will feel itself bound to do so as a consequence of the decisive popular vote for Brexit. However, Parliament may wish to delay triggering Article 50, considering that the circumstances are not right. It might even take the decision that a material change of circumstances or some other development means it is no longer bound by the referendum result. This would be intensely controversial, and perhaps unjustifiable in the absence of a second referendum vote. But it is a choice that should be available to a sovereign Parliament, given the importance of the decision at issue.

Good arguments therefore exist as to why it would be both politically expedient and constitutionally principled for Parliament to have the final say as to whether and when Article 50 should be triggered. The focus on the legal arguments being thrown about at present risks muddying the waters in this regard. The Article 50 process represents a chance to start giving greater power to Parliament: the government should recognise this, instead of staying locked in its current defensive posture.

Colm O’Cinneide, Professor of Law, UCL

(Suggested citation: C. O’Cinneide, ‘Why Parliamentary Approval for the Triggering of Article 50 TEU Should Be Required as a Matter of Constitutional Principle’, U.K. Const. L. Blog (7th Jul 2016) (available at

13 comments on “Colm O’Cinneide: Why Parliamentary Approval for the Triggering of Article 50 TEU Should Be Required as a Matter of Constitutional Principle

  1. André Clodong
    July 7, 2016

    When constitutional arguments appear to be on equal ground, thus freezing the debate, common sense (as Thomas Paine would say) must join the fray. There is no disagreement today that lies were part of the campaign. It behooves therefore to Parliament to take over the debate and ultimately decide for the common good.

  2. Mike Fearon
    July 7, 2016

    This is straying beyond the legal debate, but I find two things difficult to accept in this, and other contributions.

    1) the idea of negotiators having to look over their shoulders at Parliamentary approval. It is no way to conduct a negotiation.

    2) the prevalent idea that “being in the single market” in the EU is more valuable to the UK than to other EU member states, particularly Germany and France. The balance is far from being clear, and the U.K. Is in a much stronger position than was suggested during the campaign (for obvious reasons) by the Remain campaign.

    It may not be easy for many people to accept, but to involve Parliament in the negotiation process too heavily may well result in a weaker, and less successful negotiation.

    It seems to me that the legal debate here is drawing to a close now. The general impression I have is that it the original premise of Parliamentary approval being required prior to an Article 50 notification is seriously undermined. Short of a successful legal challenge, I can’t see it as a sustainable argument.

    • André Clodong
      July 7, 2016

      If indeed negotiations are usually conducted by government, the agreement which is reached is usually not valid until ratification by Parliament has taken place. So having a debate in Parliament prior to the negotiations could result in a better final compromise.

  3. Clan Donald
    July 8, 2016

    Hi Colm,

    Thanks for the analysis, which I think has edged the discussion further forward a little, but as yet, and perhaps disappointingly, I do not think a genuinely persuasive argument has so far been advanced as to the necessity for Parliamentary approval in terms of ‘constitutional principle’ (or indeed ‘political prudence’, although I have the advantage of writing post-Chilcott, where little of the ‘insurance’ to which you allude seems to have been afforded Tony Blair by the 418 members and massive majority voting alongside him supporting military action in Iraq).

    For UK constitutional lawyers (which should be all of us now), there should be a deep ambiguity in their relationship with our constitution, because we all know that beneath that exquisite but brittle veneer of finely polished legal principles, the ‘Rule of Law’, ‘Separation of Powers’, ‘Collective Responsibility’ ‘Accountability’ and indeed ‘Parliamentary Democracy’ itself, lies the rotten wood of Parliamentary whips, Thatcher and Blair’s usurpation, with their ‘sofa-Cabinets’, of not only Parliament but also the wider Executive, and a broader constitutional framework, where few legally enforceable limits exist to the Prerogative, particularly in terms of ‘High Policy’, and a Judiciary with little or no established public, political or constitutional-legal standing. Against this reality, it is very difficult to conclude that the case for Parliamentary Approval based on ‘Constitutional Principle’ is, or as I explain below, even should be made out, if that is to be based on the Principle of the ‘Sovereignty of Parliament’.

    While this is the principle that has almost universally been adopted by those seeking to challenge direct application of the Prerogative, it has the unfortunate consequence of inevitably diminishing the value (legally and politically) of the referendum itself. However much comfort is taken from the ‘enduring’ and ‘flexible’ nature of our constitutional arrangements, we now find ourselves in exceptional times. Whether we are heading for a period of what I hope in those circumstances might most kindly be described as ‘mass-participation politics’ rather than something more disastrous is of course, open to conjecture, but we find ourselves on a rising tide of popular feeling (globally), with the traditional forms of the established (incumbent) political parties being pushed to the point of destruction on both sides of the Atlantic and elsewhere. Notwithstanding the many flaws in the antecedents and parameters of the referendum, the public spoke.

    The real question then in all of this, the real challenge for Constitutional Jurisprudence is what might be termed ‘Taking Votes Seriously’ (and yes, I do intend all that that means, especially for the 48%). A reresentative democracy is a representative democracy only until one day when perhaps it isn’t one any more. While I indicated above that the search for extant legal-constitutional principles that would justify Parliamentary supervision of an A50 trigger might be futile, work on establishing and attempting to determine what is actually the real live issue before us currently (and likely to be in the coming years, whatever we think about our appetite for them now), i.e., the precise Constitutional relationship between the concepts of the ‘Supremacy of Parliament’ & ‘Representative Democracy’ on the one hand and and that of a Referendum on the other whether in binding or non-binding form. It is through the application of ‘constitutional principles’ to this question that we might glimpse how genuinely flexible both our constitution and we ourselves as lawyers are, and indeed whether those principles have any genuine application in the 21st Century beyond their role in gilding our language.

  4. Graham Hathaway
    July 8, 2016

    As a strong remainer I would defer to the order of Parliamentary integrity and sovereignty over state matters. But this should be perfunctory to the prime role and duty of MPs to represent the wishes of the electorate. The electorate has spoken. Majority rules.

  5. truthaholics
    July 8, 2016

    Reblogged this on | truthaholics and commented:
    “Good arguments therefore exist as to why it would be both politically expedient and constitutionally principled for Parliament to have the final say as to whether and when Article 50 should be triggered. The focus on the legal arguments being thrown about at present risks muddying the waters in this regard. The Article 50 process represents a chance to start giving greater power to Parliament: the government should recognise this, instead of staying locked in its current defensive posture.”

  6. helenjnoble
    July 8, 2016

    Reblogged this on helenjnoble.

  7. spinninghugo
    July 8, 2016

    No doubt there are good prudential reasons for seeking a Parliamentary vote first.

    The *legal* significance of the argument that an Act is required is about devolution. If no Act is legally required it is unarguable that Scotland has any blocking power.

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  10. David. Hutchinson
    September 24, 2016

    With reference to Robert Craig’s article posted on 8 July 2016 and specifically to the following extract:

    “A fourth option

    This note argues, by contrast, that the prerogative and s 2(2) ECA are not relevant to the exercise of the executive power to trigger exit from the EU. Nor is there any need for fresh legislation. This is because there is already legislation which has been passed by parliament which provides statutory authority for executive action in this area. It therefore suspends, or places into abeyance, any prerogative source of authority to act and instead this legislation, not the prerogative, forms the legal basis for the power of the Prime Minister to trigger exit from the EU.

    The legislation is the European Union (Amendment) Act 2008 (‘the 2008 Act’) which incorporates the Lisbon Treaty into UK law and, incidentally, gives it overriding legislative force with respect to past and future ordinary legislation by inserting it, in terms, directly into s 1(2) of the ECA. Any action under Article 50, as one section within the Treaty incorporated into UK law by the 2008 Act and the ECA, therefore must be taken under the relevant statutory authorisation and operate within the four corners of the relevant legislation.

    In addition, s 6 of the 2008 Act (later replaced by the European Union Act 2011) specifically lists actions under the Treaty which require further parliamentary approval before a Minister can undertake them. Article 50 is not among those actions listed in the 2008 or 2011 Acts.

    Article 50 is therefore already incorporated in UK law by primary legislation. Executive discretion to use it has therefore already been authorised.”

    Do you or any other contributors have any comment on to the assertion in the final paragraph quoted above?


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