UK: Northern Ireland High Court Rejects Article 50 Brexit Challenge

On Friday 28 October, the Northern Ireland High Court dismissed a challenge to the government's power to begin the Brexit process by triggering Article 50 of the Treaty on European Union without the approval of Parliament.

In this note, we consider the judgement in McCord's (Raymond) Application and its implications for the parallel challenge in the English Courts in Miller & Santos.

Background and issues

On 23 June 2016, the UK voted to leave the EU by a majority of 51.9%. However, voters in Northern Ireland opted to remain in the EU by a majority of 55.8%.

The process for leaving the EU is set out in Article 50. Under this, a member state must make a decision to withdraw from the EU in accordance with its own constitutional requirements and, having done so, notify that decision to the European Council. That notification serves to trigger the commencement of a two-year period (extendable only by unanimous consent) during which the UK negotiates the terms of its withdrawal from the EU.

It is a subject of some contention whether or not a notification under Article 50 can be rescinded once given, thus halting the Brexit process. That issue was not before the Court in McCord, although it did state that once notification is given, save for some exceptional circumstance (which is not expressly provided for in Article 50) the withdrawing state and the EU are on a set course which leads to the EU Treaties ceasing to apply to the withdrawing state.

On 24 June, David Cameron made a statement in which he signalled his intention to resign as Prime Minister and indicated that it would be for his successor to decide when to trigger Article 50. It has been the government's consistent position thereafter that it may use its prerogative powers to trigger Article 50 by making the requisite notification without the need for Parliamentary approval.

Two challenges to that position were brought, and subsequently joined, in the Northern Ireland High Court. The first was by a prominent campaigner on victims' issues - Raymond McCord - and the second by a group of Northern Irish politicians and voluntary and community sector representatives. The principal arguments put forward by the applicants were as follows -

  • The prerogative power is not available in relation to the triggering of Article 50 because it has been displaced by the Northern Ireland Act 1998 (the NIA) read along with the Belfast Agreement and the British-Irish Agreement which underpin it. In these circumstances, it was contended that an Act of Parliament is required to trigger Article 50.
  • Any legislation authorising notification in accordance with Article 50 will require a Legislative Consent Motion to be granted by the Northern Ireland Assembly.
  • There are a variety of public law restraints on any exercise of prerogative power, including the requirement to take all relevant considerations into account and not to give excessive weight to the referendum result.

The applicants additionally argued that the prerogative power had been displaced by the European Communities Act 1972 (ECA) - the same argument that is before the courts in England and Wales in the Miller & Santos litigation. However, these arguments were stayed by the Northern Ireland High Court, pending the outcome of the case in London, and therefore avoiding the risk that the courts in Belfast and London might reach different conclusions on the same legal issue. The only arguments considered in McCord were the specific Northern Ireland ones mentioned above.

The Court dismissed the applications on all of these grounds.

The Court's determination

The availability of the prerogative

Prerogative powers are a set of residual powers exercised by the executive, notionally on behalf of the monarch. They include the right to enter into and withdraw from international treaties. All parties in the case agreed that the availability of prerogative powers in any particular case may be removed by Parliament through legislation covering the area in which they are sought to be exercised.

The government argued that, in order for legislation to displace the prerogative, either express words were required or the displacement must be a necessary implication of the operation of the statute. The applicants argued for a broader and more flexible approach.

Having surveyed the authorities, the Court held that there was no bright line rule in this area. If there is no express statutory language limiting the operation of the prerogative, that fact will be highly relevant. Absent this, the prerogative may be displaced only by necessary implication which, following previous authority, must be one which necessarily follows from the express provisions of the statute construed in their context. It will be a matter of logic to determine if this is the case, by reference to what Parliament included in the statute rather than what it might have been sensible or reasonable to include if Parliament had thought about it.

In addition the following factors will also be relevant -

  • The statute must occupy the specific ground hitherto occupied by the prerogative. In other words, the statute must empower the doing of the very thing which the prerogative has dealt with up to the point of statutory intervention.
  • The intervention by the statute must be direct in its effect on the subject matter in question and not the result of a 'side wind'.
  • The juxtaposition of the parallel sources of authority must be such that the use of the prerogative power would be incompatible or inconsistent with the relevant statutory provision.

The applicants submitted that the NIA displaced the prerogative as it contains provisions predicated upon continuing membership of the EU. For example, it limited the legislative competence of the Northern Ireland Assembly such that it cannot pass laws which conflict with EU laws. In addition, intergovernmental bodies established jointly with the Republic of Ireland as part of the peace process - such as the North/South Council - had functions predicated on the continuing effect of EU law.

Although the applicants accepted that there were no express provisions in the NIA which displaced the prerogative, the territory dealt with by many of its provisions undermined the use of the prerogative to trigger Article 50 on the basis that it would set in train a process that would lead to EU law ceasing to have effect.

However, the Court (Mr Justice Maguire) disagreed. The provisions pointed to by the applicants were concerned not with the limitation of prerogative powers, but the operation of the Northern Ireland Assembly in line with the existing law, including EU law. The prerogative was not displaced by necessary implication as the triggering of Article 50 will not, of itself, have any effect on EU law as it applies in the UK. The notification would not change the rights of individuals or the operation of institutions, which would still continue as before until such time as the effect of Brexit would become clearer.

The need for a Legislative Consent Motion

Having dismissed the argument that an Act of Parliament would be necessary to trigger Article 50, there was no need for the Court to consider whether a Legislative Consent Motion was necessary before such legislation was passed. It did so, however, in the event that it was wrong in its determination of the main issue.

Under section 5(6) of the NIA, the UK Parliament retains the power to make laws for Northern Ireland. The applicants' case was based not upon a statutory requirement for consent but upon a constitutional convention - the Sewel convention - under which the UK Parliament will not normally make laws with regards to devolved matters without the consent of the Northern Ireland Assembly.

Again, Maguire J was unconvinced, pointing to the fact that under the NIA, matters relating to the EU were not matters that had been devolved to the Assembly. As such, legislation regarding the EU was not legislation with regard to devolved matters and, even if it was, the fact that the convention stated that consent would 'normally' be sought did not mean that it was required in every case - whether or not it was sought in any case would be an essentially political decision.

The exercise of the prerogative in line with public law principles

In the event that the Court did not agree that prerogative powers were unavailable to the government, the applicants contended that those powers must be exercised in line with the general principles of public law. They asserted that the prerogative can only be exercised -

  • in a way which is not inconsistent with Northern Ireland's unique constitutional place in the UK;
  • after properly having taken into account and having enquired into all relevant alternatives to the entirety of the UK exiting the EU;
  • only if the Government has not given excessive weight to the result of the referendum held on 23 June 2016;
  • in a manner which upholds EU law for so long as it remains effective in the UK; and
  • in a manner which respects obligations of the UK such as those arising under the British-Irish Agreement (the agreement between the UK and the Republic of Ireland as part of the peace process).

Maguire J referred to previous authority regarding the unavailability of judicial review in relation to the use of the prerogative in 'matters of high policy'. He concluded that a decision, made at the most senior level in UK politics, to give notice of withdrawal from the EU by the United Kingdom following a national referendum, must fall into the category of matters of high policy which are non-justiciable by the Court in judicial review proceedings.


It is important first to note what the Court did not say. The Court did not find that all of the issues raised by the applicants in relation to the triggering of Article 50 were non-justiciable. It held that - in circumstances where the government could lawfully use prerogative powers to trigger Article 50 - its use of those powers to do so would be one of those quintessentially political decisions that the Court would be slow to overturn on standard public law grounds.

That finding is unsurprising. The Court is reticent in judicial review proceedings to trespass into the field of political decisions which it is properly the place of the democratically elected government to make. It is hard to think of a more political decision than that regarding whether or not to trigger Article 50 and thus to leave the EU.

However, the Court displayed no reticence regarding whether or not the government could use the prerogative to trigger Article 50. That is a question of law, not politics, and one which falls squarely within the remit of the Court, even if how it uses any available prerogative power does not.

Readers will be aware that the Court in England and Wales is currently considering the same issue in Miller & Santos v Secretary of State for Exiting the European Union, the hearing for which concluded on 18 October. So to what extent does the decision in McCord affect or pre-empt the decision in Miller & Santos?

In our view, not greatly. Maguire J was careful to state that his finding on the availability of the prerogative was without prejudice to any subsequent finding in Miller & Santos.

It is important that McCord focused on the extent to which the prerogative was restrained by the specific Northern Ireland legal context, rather than by UK-wide legislation. The applicants contended that the availability of the prerogative was constrained by the effect of the NIA. The fact that this submission did not gain traction with the Court is unsurprising as it is difficult to argue that the NIA has the effect of displacing the prerogative in this area by necessary implication. The availability of EU law in the UK is not the NIA's main concern and it is mentioned simply as a part of the existing legal landscape within which the Northern Ireland Assembly must exercise its competence - albeit that it serves as an important restraint on that competence.

By contrast, the claimants in Miller & Santos argue that the prerogative is displaced by the ECA. This is a much easier case to make, as the ECA was explicitly intended to facilitate the UK's membership of the European Economic Community (as it then was). It occupies the relevant territory of the application of EU law in the UK in a way in which the NIA simply does not and better lends itself to the contention that to trigger Article 50, and thus set in motion a process through which EU law will cease to apply in the UK, is directly contrary to the intention of Parliament.

Just because the applicants in McCord were unsuccessful in arguing that the NIA did not displace the prerogative power to trigger Article 50 does not mean that the claimants in Miller & Santos will not be successful in asserting that the ECA does so. The latter is by far the stronger of the two arguments.

Finally, an interesting point is that the Court in McCord did not consider itself to be concerned about how the actual decision to leave the EU is made under the UK's constitutional requirements - just the process for notifying the European Council once it has been made.

That issue is, however, a live one in Miller & Santos.The government asserts that the result of the referendum constitutes the decision, whereas the Claimants respond that the referendum was merely advisory and that the decision remains to be made. Indeed, the claimants in Miller & Santos are clear that focus on the notification rather than the decision itself is a device by the government to allow it to argue that it is merely taking an administrative step to give effect to a decision that has already been taken, whereas this is not in fact the case. It is unclear whether the applicants in McCord did not seek to counter the government's position in this regard.

In terms of where the applicants in McCord go from here, as in Miller & Santos, there is the possibility of a leapfrog appeal to the Supreme Court where the two cases would in all likelihood be joined with a view to final determination before the end of the year.

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.

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