Canada: Parliament Must Trigger Brexit - The High Court Decision In Miller And Dos Santos

Last Updated: November 10 2016
Article by John P. Cooper and Kieran Laird

Most Read Contributor in Canada, October 2018

The Divisional Court has this morning (3 November) handed down the judgment in Miller and Dos Santos v Secretary of State for Exiting the European Union.

In a unanimous verdict, the Court determined that the decision to trigger Article 50, and so to begin the process that will lead the UK out of the EU, is for Parliament to make. The government cannot, as it had argued, use its prerogative powers to do so.

Here, we consider the first instance judgment in one of the most important constitutional cases ever to come before the UK courts.

Background and issues

The process for leaving the EU is set out in Article 50 of the Treaty on European Union.

Under this, a member state must make a decision to withdraw from the EU in accordance with its own constitutional requirements (Article 50(1)) and, having done so, notify that decision to the European Council (Article 50(2)).

That notification serves to commence a two year period (extendable only by unanimous consent) during which the UK negotiates the terms of its withdrawal from the EU.

The government's position is that the result of the EU referendum held on 23 June 2016 constitutes a decision for the purposes of Article 50(1) and that, following this decision, the government may use its prerogative power to give the notification under Article 50(2). On this analysis, that notification will simply be an administrative act following on from the decision already taken. In the alternative, the government argued that it could use the prerogative to make the decision to leave in any event.   

As we have outlined in a previous alert, the two individual claimants in this case are Gina Miller and Deir Dos Santos. They were joined by a supporting cast of interested parties and interveners.

The Claimants and the interested parties disagree with the government's position, with most arguing that an Act of Parliament is necessary before notification under Article 50(2) may be given.

This, they argue, is because prerogative powers are not available where their use would frustrate the will of Parliament as outlined in statute. In this case, the European Communities Act 1972 (the ECA) gave domestic effect to a range of rights under EU law which would cease to be available once the UK left the EU. Although some of those rights (such as employment rights) could be replicated in UK law, others (such as the right to free movement throughout the EU) could not. The giving of the Article 50 notice by the government would therefore pre-empt any ability of Parliament to decide on whether those statutory rights should be changed.

The Claimants also argue that, although Parliament will have an opportunity to decide whether or not to ratify any withdrawal agreement negotiated with the EU, this will not cure that pre-emption as, by that point in time, it would not be possible to reverse the UK's withdrawal from the EU. Importantly, the government conceded the issue of the irrevocability of an Article 50 notice. 

In the words of the Court: "Once the notice is given, it will inevitably result in the complete withdrawal of the United Kingdom from membership of the European Union and from relevant Treaties at the end of the two year period" (subject only to any extension of this timetable).

The Court's determination

The Court – comprising the two most senior judges in England and Wales (the Lord Chief Justice and the Master of the Rolls) together with Lord Justice Sales – found for the Claimants.

The Court took as its point of departure the government's contention that the content of the rights given effect by the ECA is defined by reference to the EU Treaties. On the government's case, Parliament had intended the continued existence of those rights to be conditional upon the UK's continued membership of the EU, and that membership depends on the actions of the Crown on the plane of international law. 

The argument was therefore that, absent any express wording constraining the use of the prerogative, the intention of Parliament in the ECA was actually that EU rights would at any time be vulnerable to action by the government.

The Court, in a unanimous judgment, considered that this went much too far. As a matter of law, there must be express language, or a clear necessary implication, that Parliament has intended a statute to depart from important constitutional principles.

In this case there were two major constitutional principles in play – 

  1. that the Crown cannot use its prerogative powers to alter domestic law, and 
  2. that the Crown's prerogative power operates only on the international plane.

With respect to the first principle, the Court highlighted that the ECA has a special status, as one of a small number of 'constitutional statutes', which are exempt from the usual doctrine of implied repeal (under which a statute can be taken to be repealed simply by virtue of its inconsistency with a later statute). Given that status, and the insulation it provides from implied repeal by Parliament itself, it could not be thought that Parliament had intended that the legal effects of the ECA could be removed through use of executive action by the government.

With respect to the second principle, the Court held that the government is certainly free to use the prerogative on the international plane. However, the reason why this is the case is precisely because in doing so it has no effect on domestic law. Where – as in this case, because of the ECA – an action on the international plane would affect domestic law, it lies outside the scope of the prerogative.

Against this background, the Court considered that it was clear that Parliament had intended to legislate in the ECA to introduce EU law into domestic law in such a way that it could not be undone through use of the prerogative. The government therefore has no power to effect a withdrawal from the EU by using the prerogative to give notice under Article 50.

This decision is plainly the right one for the reasons we outlined back in July. 

It is interesting to note the comments made by the Court regarding the decision of the Northern Ireland High Court in the parallel proceedings held in Belfast (McCord's (Raymond) Application). As we have previously discussed, in McCord the High Court was considering only arguments related to the Northern Ireland legal context and, in particular, the effect of the Northern Ireland Act 1998. However, the Divisional Court in Miller and Dos Santos pointed to some errors in the McCord judgment, some of which sprang from the different way in which the two cases were argued. Those comments may give impetus to an appeal by the applicants in McCord.

Next steps

The government has confirmed its intention to appeal the judgment in Miller and Dos Santos.

The case will now be subject to a leapfrog appeal to the Supreme Court (where it may be joined by McCord) under sections 12 and 13 of the Administration of Justice Act 1969. At this morning's hearing, James Eadie QC, on behalf of the government, applied for and was granted the certificate that is the first step in that process.

This will be followed by an application to the Supreme Court for formal permission regarding a direct appeal to it. Permission will certainly be granted and the Supreme Court has already set aside some time in early December to hear the case with a view to issuing a decision before the end of the year.

The decision by the Divisional Court is therefore a dress rehearsal for a Supreme Court determination in December. However, the judgment, made by a bench including two of the most senior judges in England and Wales, may well set the weather in the Supreme Court and make an eventual victory for the Claimants more likely. 

If that happens, the Prime Minister's plan to trigger Article 50 by the end of March next year will probably need to be abandoned and MPs will have a chance to impose conditions ensuring proper Parliamentary scrutiny of the negotiations as they go forward. That is important as such scrutiny has been sorely lacking to date.  

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

To print this article, all you need is to be registered on

Click to Login as an existing user or Register so you can print this article.

In association with
Related Topics
Related Articles
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Registration (you must scroll down to set your data preferences)

Mondaq Ltd requires you to register and provide information that personally identifies you, including your content preferences, for three primary purposes (full details of Mondaq’s use of your personal data can be found in our Privacy and Cookies Notice):

  • To allow you to personalize the Mondaq websites you are visiting to show content ("Content") relevant to your interests.
  • To enable features such as password reminder, news alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our content providers ("Contributors") who contribute Content for free for your use.

Mondaq hopes that our registered users will support us in maintaining our free to view business model by consenting to our use of your personal data as described below.

Mondaq has a "free to view" business model. Our services are paid for by Contributors in exchange for Mondaq providing them with access to information about who accesses their content. Once personal data is transferred to our Contributors they become a data controller of this personal data. They use it to measure the response that their articles are receiving, as a form of market research. They may also use it to provide Mondaq users with information about their products and services.

Details of each Contributor to which your personal data will be transferred is clearly stated within the Content that you access. For full details of how this Contributor will use your personal data, you should review the Contributor’s own Privacy Notice.

Please indicate your preference below:

Yes, I am happy to support Mondaq in maintaining its free to view business model by agreeing to allow Mondaq to share my personal data with Contributors whose Content I access
No, I do not want Mondaq to share my personal data with Contributors

Also please let us know whether you are happy to receive communications promoting products and services offered by Mondaq:

Yes, I am happy to received promotional communications from Mondaq
No, please do not send me promotional communications from Mondaq
Terms & Conditions (the Website) is owned and managed by Mondaq Ltd (Mondaq). Mondaq grants you a non-exclusive, revocable licence to access the Website and associated services, such as the Mondaq News Alerts (Services), subject to and in consideration of your compliance with the following terms and conditions of use (Terms). Your use of the Website and/or Services constitutes your agreement to the Terms. Mondaq may terminate your use of the Website and Services if you are in breach of these Terms or if Mondaq decides to terminate the licence granted hereunder for any reason whatsoever.

Use of

To Use you must be: eighteen (18) years old or over; legally capable of entering into binding contracts; and not in any way prohibited by the applicable law to enter into these Terms in the jurisdiction which you are currently located.

You may use the Website as an unregistered user, however, you are required to register as a user if you wish to read the full text of the Content or to receive the Services.

You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these Terms or with the prior written consent of Mondaq. You may not use electronic or other means to extract details or information from the Content. Nor shall you extract information about users or Contributors in order to offer them any services or products.

In your use of the Website and/or Services you shall: comply with all applicable laws, regulations, directives and legislations which apply to your Use of the Website and/or Services in whatever country you are physically located including without limitation any and all consumer law, export control laws and regulations; provide to us true, correct and accurate information and promptly inform us in the event that any information that you have provided to us changes or becomes inaccurate; notify Mondaq immediately of any circumstances where you have reason to believe that any Intellectual Property Rights or any other rights of any third party may have been infringed; co-operate with reasonable security or other checks or requests for information made by Mondaq from time to time; and at all times be fully liable for the breach of any of these Terms by a third party using your login details to access the Website and/or Services

however, you shall not: do anything likely to impair, interfere with or damage or cause harm or distress to any persons, or the network; do anything that will infringe any Intellectual Property Rights or other rights of Mondaq or any third party; or use the Website, Services and/or Content otherwise than in accordance with these Terms; use any trade marks or service marks of Mondaq or the Contributors, or do anything which may be seen to take unfair advantage of the reputation and goodwill of Mondaq or the Contributors, or the Website, Services and/or Content.

Mondaq reserves the right, in its sole discretion, to take any action that it deems necessary and appropriate in the event it considers that there is a breach or threatened breach of the Terms.

Mondaq’s Rights and Obligations

Unless otherwise expressly set out to the contrary, nothing in these Terms shall serve to transfer from Mondaq to you, any Intellectual Property Rights owned by and/or licensed to Mondaq and all rights, title and interest in and to such Intellectual Property Rights will remain exclusively with Mondaq and/or its licensors.

Mondaq shall use its reasonable endeavours to make the Website and Services available to you at all times, but we cannot guarantee an uninterrupted and fault free service.

Mondaq reserves the right to make changes to the services and/or the Website or part thereof, from time to time, and we may add, remove, modify and/or vary any elements of features and functionalities of the Website or the services.

Mondaq also reserves the right from time to time to monitor your Use of the Website and/or services.


The Content is general information only. It is not intended to constitute legal advice or seek to be the complete and comprehensive statement of the law, nor is it intended to address your specific requirements or provide advice on which reliance should be placed. Mondaq and/or its Contributors and other suppliers make no representations about the suitability of the information contained in the Content for any purpose. All Content provided "as is" without warranty of any kind. Mondaq and/or its Contributors and other suppliers hereby exclude and disclaim all representations, warranties or guarantees with regard to the Content, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. To the maximum extent permitted by law, Mondaq expressly excludes all representations, warranties, obligations, and liabilities arising out of or in connection with all Content. In no event shall Mondaq and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use of the Content or performance of Mondaq’s Services.


Mondaq may alter or amend these Terms by amending them on the Website. By continuing to Use the Services and/or the Website after such amendment, you will be deemed to have accepted any amendment to these Terms.

These Terms shall be governed by and construed in accordance with the laws of England and Wales and you irrevocably submit to the exclusive jurisdiction of the courts of England and Wales to settle any dispute which may arise out of or in connection with these Terms. If you live outside the United Kingdom, English law shall apply only to the extent that English law shall not deprive you of any legal protection accorded in accordance with the law of the place where you are habitually resident ("Local Law"). In the event English law deprives you of any legal protection which is accorded to you under Local Law, then these terms shall be governed by Local Law and any dispute or claim arising out of or in connection with these Terms shall be subject to the non-exclusive jurisdiction of the courts where you are habitually resident.

You may print and keep a copy of these Terms, which form the entire agreement between you and Mondaq and supersede any other communications or advertising in respect of the Service and/or the Website.

No delay in exercising or non-exercise by you and/or Mondaq of any of its rights under or in connection with these Terms shall operate as a waiver or release of each of your or Mondaq’s right. Rather, any such waiver or release must be specifically granted in writing signed by the party granting it.

If any part of these Terms is held unenforceable, that part shall be enforced to the maximum extent permissible so as to give effect to the intent of the parties, and the Terms shall continue in full force and effect.

Mondaq shall not incur any liability to you on account of any loss or damage resulting from any delay or failure to perform all or any part of these Terms if such delay or failure is caused, in whole or in part, by events, occurrences, or causes beyond the control of Mondaq. Such events, occurrences or causes will include, without limitation, acts of God, strikes, lockouts, server and network failure, riots, acts of war, earthquakes, fire and explosions.

By clicking Register you state you have read and agree to our Terms and Conditions