Brexit Legal Challenge; an update on the Article 50 Litigation

9 November 2016

Duncan Gillespie

On 3 November the High Court delivered its judgement in the case brought by Ms Gina Miller and others against the Secretary of State for Exiting the European Union in which Ms Miller had argued that an Act of Parliament is required before the Government can initiate the process of leaving the EU provided for under Article 50 of Treaty on European Union.

As described below, Ms Miller’s claim was successful but the Government has said that it will appeal to the Supreme Court.  That appeal is scheduled to be heard between 5 and 8 December with duration depending upon the complexity of the legal submissions made and the number of interveners.  In keeping with the constitutional significance of this case, it will be decided by all 11 Supreme Court judges.



As is now well known, under Article 50 a Member State that wishes to withdraw from the EU must notify the European Council of its decision.  An agreement on the terms of withdrawal will then be negotiated with the withdrawing Member State by the Council on behalf of the continuing EU.[1]

The withdrawal agreement will take account of the likely nature of the future relationship between the continuing EU and the departing Member State (e.g. in relation to continued access to the single market) but will not cover those arrangements in detail, being more in the nature of a “divorce settlement” dealing with practical matters such as winding up of EU-funded programmes in that country, its ongoing liability for contributions to EU staff pension funds, etc.

Unless extended by a unanimous decision of the remaining EU Member States, the period for negotiation of the withdrawal agreement will expire (and with it the departing Member State’s membership of the EU) two years after delivery of the notification under Article 50 whether or not a withdrawal agreement has been concluded, still less an agreement on the ongoing relationship between that Member State and the continuing EU which is likely to take far longer.

It should be noted that, contrary to some newspaper reports, both parties agreed that the Article 50 process cannot be reversed and, once initiated, would lead to the UK’s exit from the EU irrespective of whether an acceptable deal (to the UK) had been done on e.g. single market access.  Therefore, even if the terms of any deal were regarded by Parliament as unsatisfactory when put to it for ratification, there would be little that Parliament could do about it (the 2 year negotiating window having expired) hence its only option other than putting up with it would be to veto it in its entirety.

Ms Miller’s case was that membership of the EU confers rights upon UK citizens that go beyond those available to them under UK law.  Those rights fall into three categories:

(i)        Those deriving from EU law that could be replicated (at least to some extent) under UK law, e.g. the protection given to workers under the Working Time Directive;


(ii)       Those available to UK companies and individuals as a consequence of the UK’s membership of the EU, e.g. the free movement of persons, goods/services and capital and the right of a company to establish in any EU Member State; and


(iii)      Those deriving from EU law that could not be replicated in domestic law, e.g. the right to vote in and stand for election in any Member State and the right to bring alleged violations of EU law to the attention of the European Commission for investigation and sanction.


Withdrawal from the EU would (unless a suitable deal could be done with the EU) entail the loss of those rights, albeit Parliament could legislate to reinstate equivalent protections to category (i).

Ms Miller argued that since the Civil War the Crown or, as more recent convention has it, Government ministers acting in the name of the Crown, have been legally prohibited from taking decisions that infringe the rights of the citizens (whether these arise under common law or legislation) without Parliamentary authority, normally in the form of an Act of Parliament.

Since invoking Article 50 would inevitably lead to the UK’s withdrawal from the EU and therefore to the loss of those rights unless an acceptable deal could be done with the continuing EU (which could not be known in advance), a decision to invoke Article 50 would in effect be a decision by the Government to remove rights enjoyed by UK citizens.  Ms Miller therefore argued that this would be unlawful without the approval of Parliament.

The Government’s arguments in response were:


  • It had stated before the referendum that it would abide by the result whatever it turned out to be.  The result was that the UK should leave the EU with all that that entails.  Accordingly, the proper course is for the Government to begin the Article 50 withdrawal process;


  • It is long established law that the Government has the right to exercise the Royal Prerogative (i.e. to operate without Parliamentary authority) in foreign affairs – e.g. to enter into or withdraw from international treaties without consulting Parliament in advance.  Parliament’s role in such cases is to decide whether or not to ratify such treaties after they are agreed.  The Article 50 process falls within the Royal Prerogative and Parliament will have the opportunity to scrutinise any agreement that is reached with the EU at the conclusion of that process, but is not entitled to prevent it from being initiated;


  • Express provision would need to have been made in legislation to displace the Royal Prerogative in this respect and no such provision had been made; and

  •  A decision by the Government whether or not to invoke Article 50 is not susceptible to review by the Courts.  It is a matter for Parliament itself and the Court should not trespass on Parliamentary proceedings.


In response to arguments put forward by interveners in the proceedings that invoking Article 50 without the approval of Parliament and possibly that of the devolved administrations in Scotland, Wales and Northern Ireland would violate the devolution settlements and, in the case of Scotland at least, the Acts of Union, [2] the Government stated that the conduct of foreign affairs is a “reserved matter” and therefore not within the legislative competence of any of the devolved administrations hence this point is essentially irrelevant.


The Court’s Findings

The Court began by affirming the long-established doctrine that the bedrock of the British constitution is the supremacy of Parliament.

This has the interesting corollary that, as set out by Professor Dicey, the great jurist of the late 19th/early 20th centuries, an Act of Parliament can never be declared invalid merely on the ground that it is said to go against the popular will.

The Court then went on to examine the extent of the Royal Prerogative, i.e. the power of the Government of the day to act either in opposition to an Act of Parliament or to by-pass Parliament entirely in taking a particular decision.  Again, the Court affirmed the accepted position that “the Crown only has the prerogative powers recognised by the common law and their exercise only produces legal effects within the boundaries so recognised”.  Any attempt to use the Royal Prerogative outside those boundaries would therefore be unlawful.

The Court accepted that the conduct of international relations is one area where the Royal Prerogative continues to operate.  Accordingly the Court agreed with the Government that it is entitled to make and unmake international treaties but noted that the reason why the Royal Prerogative continues to apply in this area is precisely that by making or unmaking treaties the Crown creates legal effects in the international arena but in doing so it does not and cannot change domestic law: “It cannot without the intervention of Parliament confer rights on individuals or deprive individuals of rights”.

Put the other way round, the Government’s freedom to continue to make or unmake international agreements without prior Parliamentary scrutiny is conditional upon those international agreements having no effect on the private rights of UK citizens.

The Court went on to find that, contrary to the Government’s suggestion, Parliament had not either explicitly or by implication legislated to extend the Royal Prerogative such that the Government could abolish the rights of UK citizens under EU law without recourse to Parliament.  In fact, by enacting the European Communities Act 1972 (which incorporated EU law into UK law and provided for its supremacy over domestic law) Parliament had legislated to limit the Royal Prerogative here.

The Court also noted that, applying the constitutional principles set out above, in particular that of the supremacy of Parliament, the outcome of the referendum could only ever have been advisory – i.e. it did not bind Parliament, albeit no doubt Parliament would give the highest consideration to it.

Consequently, the Court found that the Government does not have the power to give notice under Article 50 of the Treaty without the authorisation of Parliament (in the form of an Act of Parliament).

In the circumstances, the Court did not feel that it needed to address the arguments based on the devolution settlements as these would not have affected the outcome either way.


Where does this leave us?

The Government has indicated that it is likely to appeal the Court’s judgment and that appeal is scheduled to be heard early next month.

If the appeal is successful the Government will presumably go on to invoke Article 50 as planned.  If, on the other hand, the Supreme Court upholds the High Court’s decision then it would appear that an Act of Parliament would be required before Article 50 could be invoked.

It is suggested that a majority of MPs were in favour of remaining in the EU but whether they would be prepared to go against the will of the majority of the electorate by voting against a Brexit bill must be in doubt, though the indications are that the SNP MPs at least will do so.  The House of Lords is also thought to be pro-remain and obviously not subject to the will of the electorate in the same way as the Commons.

A Brexit bill sponsored by the Government would be likely to be seen as a confidence matter and any failure of it to pass would almost certainly trigger a General Election.  The outcome of any such election for Brexit would depend upon whether the winning party had stood on a manifesto commitment to deliver Brexit.  At the time of writing this clearly cannot be known.

In fact, it is speculated that, rather than risk defeat in Parliament, the Government would call a General Election on this issue.

In conclusion, therefore, there is some way to go before we can say with confidence if, and when, the Brexit process will be initiated.

Of course, even if Brexit were to go ahead, EU law would continue to apply for at least two years while the Article 50 process worked through and, even then, depending on the nature of the deal with the continuing EU, it seems likely that substantial elements of EU law (or very close equivalents) will continue to apply post-Brexit, e.g. in relation to competition, environmental matters, food standards and data protection to name but a few.

The  message for business is therefore that nothing has changed for the present but that a watching brief should be maintained.

Please contact Duncan Gillespie if you wish to discuss any matters arising from this note.


[1] Note that, confusingly, the European Council and the Council are different institutions.

[2] There are two Acts of Union, one passed by each of the former English and Scottish Parliaments.