Is it rational to trigger Article 50?



The present Government proposes that the United Kingdom withdraw from the European Union following a referendum on the issue in June 2016. A Bill giving the decision on triggering the process to withdraw to the Prime Minister is going swiftly through Parliament. This article considers how a Prime Minister must exercise her judgment in taking that decision, by considering the following questions:


  • Discretion and reason – What is discretion and exercise of judgement; and how is it affected by operation of the rationality of the decision-maker (ie the Prime Minister in this case)?
  • Referendum result – How does reason apply to the referendum result; and how far was the result ‘advisory’?
  • Rights and EU withdrawal – How does the treatment of rights in EU withdrawal apply to an exercise of reason?


The EU withdrawal issue has been twice before the courts in recent months: before the Divisional Court in R (Miller & Anor) v The Secretary of State for Exiting the European Union [2016] EWHC 2768 (Admin) ( and the Supreme Court as R (Miller & anor) v Secretary of State for Exiting the European Union [2017] UKSC 5 ( They will be referred to as Miller 1 and Miller 2 respectively.


These cases resolved only whether the Government must have Parliament’s permission – that is, an Act of Parliament – for the Prime Minister to trigger the process for UK’s coming out of the EU and by activating Treaty of European Union 1992 Article 50. At the time of writing there is a Bill before Parliament (set out below) which will do what the two courts said the Government must do.


This article concerns only the narrow point of what should operate on the mind of the Prime Minister when she considers the rationality of whether or not to trigger Art 50. In particular it will look at this in the light of two points: (1) the advisory nature of the referendum and (2) the rights of UK nationals and EU members engaged.





Exercise of discretion


Any Minister to whose job is to exercise a discretion, or judgment in the making of a decision, must exercise it rationally. If judgment is exercised by a Government minister it must be exercised wisely and according to the law. It must be exercised according to reason, and not in an arbitrary way. Administrative Law (2014) Wade & Forsyth (11th Ed), often quoted by


A minister’s reasoning depends on appropriate information being provided to him/her. If appropriate information is provided and understood the minister has a firm foundation for making a decision. If there is a choice of courses, the minister decides by exercise of discretion. That exercise of discretion is governed by the same legal principles in 2017 as over 400 years ago in Rookes Case. In that case in 1598 the report, by Edward Coke, later Sir Edward Coke, said of the exercise of discretion of commissioners of sewers:


That they should do according to their discretions, yet their proceedings ought to be limited and bounded within the Rules of Law and Reason; for that discretion is a Science to discern betwixt falsity and truth, between right and wrong, between shadows and substance, betwixt equity and colourable glosses, and the Commissioners ought not to follow their wills and private affections;


The rationality of any exercise of discretion can always be brought into question. Statutory power is, in a sense, vested in a minister on trust for the governed as a whole. Therefore ‘unfettered governmental discretion is a contradiction in terms’ (Administrative Law (above) at p 295). The modern statement of the law on this is Padfield v Minister of Agriculture, Fisheries and Food [1968] AC 997, [1968] 2 WLR 924 where a majority (four to one) in the House of Lords refused to permit a government minister to act in a way which, they said, was no in accordance with the Act of Parliament under which he proceeded (in that case with complaints from farmers about a Milk Marketing Board pricing scheme).


Lord Reid explained his view of the law after first saying that, it seemed to him, that the minister was trying to argue that there could only be ‘two possible interpretations of this provision either he must refer every complaint or he has an unfettered discretion to refuse to refer in any case.’ Lord Reid refused to accept this argument by the Minister:


I do not think that is right. Parliament must have conferred the discretion with the intention that it should be used to promote the policy and objects of the Act, the policy and objects of the Act must be determined by construing the Act as a whole and construction is always a matter of law for the court. In a matter of this kind it is not possible to draw a hard and fast line, but if the Minister, by reason of his having misconstrued the Act or for any other reason, so uses his discretion as to thwart or run counter to the policy and objects of the Act, then our law would be very defective if persons aggrieved were not entitled to the protection of the court. So it is necessary first to construe the Act.


Prime Minister’s discretion


That is, according to Padfield, it is necessary to find out first what a relevant Act intends. The problem with the European Union (Notification of Withdrawal) Bill – and it is still a Bill – is that it does not say what it intends beyond giving authority ‘to notify’ the UK’s intention to leave the EU. Clause 1(1) says, under the heading ‘1 Power to notify withdrawal from the EU’:


(1) The Prime Minister may notify, under Article 50(2) of the Treaty on European Union, the United Kingdom’s intention to withdraw from the EU.


And therein lies the discretion: the Prime Minister ‘may notify’. She has to decide. In so doing she must act rationally. Underlying that rationality question it is critical for her to be clear – and preferably to say that she is clear – what is meant by the 2016 referendum. Secondly, she needs to understand as fully as possible what will be changed adversely to those she represents – the UK nationals affected in the variety of ways involved – as a result of triggering Article.


The first of these points – the advisory nature of the referendum – has been explained to her, or for her, by the High Court and Supreme Court. The second could not have informed the electorate’s mind when they voted in the referendum – as she well knows. She knows this because neither she nor the army of civil servants working on the question have begun to give her an informed view of it all – eg by presenting or publishing a draft ‘Great Reform Bill’.


So that takes us back to Coke and what is meant by the discretion she has been given by s 1(1) and how she exercises it.





Meaning of the 2016 referendum


The referendum issue can be approached in this way. In December 2015, the UK Parliament passed the European Union Referendum Act 2015. The ensuing referendum on 23 June 2016 produced a majority of those who voted, favour of leaving the European Union. UK government ministers then announced that they would bring UK membership of the European Union to an end.


The effect of any referendum said the Supreme Court in Miller 2 depends on the following:


[118] … the terms of the statute which authorises it. Further, legislation authorising a referendum more often than not has provided for the consequences on the result. Thus, the authorising statute may enact a change in the law subject to the proviso that it is not to come into effect unless approved by a majority in the referendum


The 2015 Act did not state what the outcome of the referendum was to mean. It left what was to happen next open. No provision was made in the Act for the consequences of the referendum. The earlier 1975 referendum was described by ministers as advisory, whereas the 2016 referendum was described as advisory by some ministers and as decisive by others. So how had ministers seen the question of outcome of the referendum, asked the Supreme Court:


[125] It is instructive to see how the issue was addressed in ministers’ response to the 12th Report of Session 2009-10 of the House of Lords Select Committee on the Constitution (Referendums in the United Kingdom). The Committee included the following recommendation in para 197:

“[B]ecause of the sovereignty of Parliament, referendums cannot be legally binding in the UK, and are therefore advisory. However, it would be difficult for Parliament to ignore a decisive expression of public opinion.”

The UK government’s response as recorded in the Committee’s Fourth Report of Session 2010-11 was

“The Government agrees with this recommendation. Under the UK’s constitutional arrangements Parliament must be responsible for deciding whether or not to take action in response to a referendum result.”


The courts and the referendum: ‘advisory’ said the High Court


So in 2010 ministers were told the referendum ‘cannot be legally binding’, and are therefore ‘advisory’; and in 2011 ‘Parliament must be responsible’ for any decision. In the Divisional Court in Miller 1 the judges drew attention to the parliamentary briefing paper No 7212 Pt 5.


[107] Further, the 2015 Referendum Act was passed against a background including a clear briefing paper to parliamentarians explaining that the referendum would have advisory effect only. Moreover, Parliament must have appreciated that the referendum was intended only to be advisory as the result of a vote in the referendum in favour of leaving the European Union would inevitably leave for future decision many important questions relating to the legal implementation of withdrawal from the European Union.


The ‘briefing paper’ referred to in §107 is set out in Annex 1 to this article. The passage which is likely to have been in members’ minds when they voted for the 2015 Act, and should be in Mrs May’s mind now, is in Pt 5 as follows:


[The Referendum Bill (as it was then)] does not contain any requirement for the UK Government to implement the results of the referendum, nor set a time limit by which a vote to leave the EU should be implemented. Instead, this is a type of referendum known as pre-legislative or consultative, which enables the electorate to voice an opinion which then influences the Government in its policy decisions.


The Supreme Court decision in Miller 2 was, in the end, expressed by the majority as simply as:


[124] Thus, the referendum of 2016 did not change the law in a way which would allow ministers to withdraw the United Kingdom from the European Union without legislation. But that in no way means that it is devoid of effect. It means that, unless and until acted on by Parliament, its force is political rather than legal. It has already shown itself to be of great political significance.





EU rights lost by withdrawal: the judge’s view


If new legislation is planned the Government department publishes a green paper for discussion of a subject and for it to receive views. A white paper can then follow to set out Government policy and is likely to be followed by a bill setting out proposed new law. Here there has been a four line bill (awaiting its third reading as I write). There has been no green paper; and a white paper emerged from the Government whilst the bill was going through Parliament.


So what is the Government’s understanding of rights which may be lost – to EU nationals in the UK, and to UK nationals in the EU – by EU withdrawal? This should perhaps be uppermost in a reasonable Prime Minister’s mind if she considers the triggering of Art 50?


In Miller 1 the Divisional Court explained that under European Communities Act 1972 s 2(1) rights had been incorporated into – ‘given legal effect’ under – UK law (§§[57]-[66]). The court identified three categories of rights under ECA 1972 and EU law (a categorisation accepted by the Supreme Court: see Miller 2 at §69) which would be affected or lost as a result of EU withdrawal:


  • Rights capable of being reproduced in UK law;
  • Rights derived by UK citizens from EU law in other member states;
  • Rights of participation in EU institutions that could not be replicated in UK law.


The Supreme Court explained that, in general terms (at §69) ‘our domestic law will change as a result of the United Kingdom ceasing to be party to [the EU treaties], and rights enjoyed by UK residents granted through EU law will be affected’. The Supreme Court went on, at §§70-72 to give examples of these rights. For example in category (1), a lengthy paragraph included:


[70] … They include, for instance, the rights of UK citizens to the benefit of employment protection such as the Working Time Directive, to equal treatment and to the protection of EU competition law, and the right of non-residents to the benefit of the “four freedoms” (free movement of people, goods and capital, and freedom to provide services)….


The Divisional Court explained the consequences for these rights as follows:


[64] As to category (1) rights, we consider that the claimants are correct in their submission that it is the ECA 1972 which is the principal legislation under which these rights are given effect in domestic law of the United Kingdom: and that it is no answer [by the Government] to their case to say that some of them might be preserved under new primary legislation, yet to be enacted, when withdrawal pursuant to Article 50 takes place. The objection remains that the Crown, through exercise of its prerogative powers, would have deprived domestic law rights created by the ECA 1972 of effect….


What the Divisional Court said of category (2) rights included the following (italics added):


[65] … The reality is that Parliament knew and intended that enactment of the ECA 1972 would provide the foundation for the acquisition by British citizens of rights under EU law which they could enforce in the courts of other Member States. We therefore consider that the claimants are correct to say that withdrawal from the European Union pursuant to Article 50 would undo the category (2) rights which Parliament intended to bring into effect, and did in fact bring into effect, by enacting the ECA 1972. Although these are not rights enforceable in the national courts of the United Kingdom, they are nonetheless rights of major importance created by Parliament.


The Prime Minister on rights


So what does the Prime Minister, who is to sign off Art 50(2), think of all this? We have her 17 January 2017 speech and the White Paper to test this. What do these say on the subjects? This and the white paper is the only real test, so far, of her reasoning on the subject. Her speech of 17 January said that


… we will take back control of our laws and bring an end to the jurisdiction of the European Court of Justice in Britain. Leaving the European Union will mean that our laws will be made in Westminster, Edinburgh, Cardiff and Belfast. And those laws will be interpreted by judges not in Luxembourg but in courts across this country.


So what laws did she have in mind, bearing in mind what the judges had said on the subject:


We want to guarantee the rights of EU citizens who are already living in Britain, and the rights of British nationals in other member states, as early as we can. I have told other EU leaders that we could give people the certainty they want straight away, and reach such a deal now.


Mrs May suggests surprise in her speech that not all EU members will agree; and if they will not where does that leave category (2) rights? Is that of concern to her? She does not say. It is a matter which, it could be argued, should act on her mind before she triggers Art 50.


She then dealt with protection of ‘workers’ rights’. ‘A fairer Britain’ is a country ‘that protects and enhances the rights people have at work…. we will ensure that workers’ rights are fully protected and maintained.’ She did not distinguish between rights of workers in the UK, and of UK nationals in EU countries.


EU withdrawal White Paper: treatment of rights


The Government’s White Paper, ‘The United Kingdom’s exit from and new partnership with the European Union’, February 2017 (Cm 9417) ( put a little flesh on the bones of Mrs May’s 17 January speech. (It is that White paper which included – with only one verb, ‘’s’, in the quoted paragraph (on page 3) – the remarkable: ‘And another thing that’s important. The essential ingredient of our success. The strength and support of 65 million people willing us to make it happen.)


The contents page of the White Paper is set out at the end of this article (Annex 2). It says the White paper deals with rights in two contexts only:


  • Securing rights for EU nationals in the UK, and UK nationals in the EU
  • Protecting workers’ rights


The White Paper does not attempt to list these rights nor to deal with them in the way that the two judgments do. Still less does the White Paper produce the Government’s promised – or is it? – Great Repeal Bill. Securing rights for EU nationals, and for UK nationals in the EU is dealt with in two page; and one of those pages is mostly graphs. The second page includes:


6.3 Securing the status of, and providing certainty to, EU nationals already in the UK and to UK nationals in the EU is one of this Government’s early priorities for the forthcoming negotiations…

6.4 The Government would have liked to resolve this issue ahead of the formal negotiations. And although many EU Member States favour such an agreement, this has not proven possible. The UK remains ready to give people the certainty they want and reach a reciprocal deal with our European partners at the earliest opportunity. It is the right and fair thing to do.


These two paragraphs – on which the rights for the future a number of people depend – represents no substance: not what rights are engaged and how they will be dealt with, for example. As far as it goes – and that is not very far – it is little more than hope and a little recrimination. There is not reflection that if things like this had been considered with EU partners (as they still are) before a decision to leave, they might have been a little keener to help. Mrs May seems a remarkably naive negotiator, but perhaps that goes with bossiness.


‘Workers’ rights’ get even less: one page, two paragraphs and no graphs. And that is it on the rights sections. Compare the White Paper with the efforts to provide information in the two court judgements and that put into production of a White Paper which should have been in gestation since June last year, and you realise how this country is served by its judges as against by its government.





How to define the nut; defining the rights lost


In the case of R (Quila & anor) v Secretary of State for the Home Department [2011] UKSC 45, [2012] 1 AC 621, [2012] 1 FLR 788 ( the Supreme Court were concerned with a Home Office regulation which – to help to combat forced marriages, it was said – raised the age for immigration to the UK for marriage to 21. Such evidence as there was suggested that many more unforced marriages would be impeded than forced marriages prevented. Had the Secretary of State (Mrs May, as it happens) acted rationally in deciding to agree to the regulation?


No said Lord Wilson (with whom three of the other four Supreme Court Justices agreed). She had identified a nut, but failed to identify the size of the nut to which she was taking a sledge-hammer:


[58] … The number of forced marriages which [the regulation] deters is highly debatable. What seems clear is that the number of unforced marriages which it obstructs from their intended development for up to three years vastly exceeds the number of forced marriages which it deters. Neither in the material which she published prior to the introduction of the amendment in 2008 nor in her evidence in these proceedings has the Secretary of State addressed this imbalance – still less sought to identify the scale of it. Even had it been correct to say that the scale of the imbalance was a matter of judgement for the Secretary of State rather than for the courts, it is not a judgement which, on the evidence before the court, she has ever made…. On any view it is a sledge-hammer but she has not attempted to indentify the size of the nut.


Leaving the EU is the sledge-hammer which the referendum has advised Mrs May – no more than advised – to wield. One aspect of the nut – the problems which, it is thought, EU withdrawal would solve and the advantages it create – can no doubt be guessed at by any number of Brexit enthusiasts. But – the other aspect of the nut – a reasonable person must weigh all matters in the balance.


Rights of UK nationals and EU members to be lost


The factors the Prime Minister must put in the balance – and which she might have to explain to a High Court judge (the equivalent of the number of unforced marriages in the Quila case) – have not been explained by her to us. The White Paper does not do it. Amongst these factors, it might be thought by her, are the loss or disruption of many rights which go for EU members in the UK and UK nationals in the EU; workers’ rights; rights on family breakdown and for children if parties live in UK and EU respectively. Many more such rights have yet to be clarified and their future enacted into draft legislation. (Had they been defined by a Government department it is most likely we would have a draft ‘Great Reform Bill’ by now.)


It is the Prime Minister’s decision if the Bill is passed. She does not have to say how she reaches her decision, but the less she says the more she may have to explain later. Within the range of the two areas covered in this article – the size of the rights ‘nut’ and an understanding that the referendum was ‘advisory’ of MPs only – it can be said of the Prime Minister’s decision that two conclusions follow.


First, for the Prime Minister to proceed on the basis that she must withdraw UK from the EU because it is the ‘will of the people’ is wrong. Constitutional principle (supported by the 7212 briefing paper (Annex 1 below) and the Divisional Court and Supreme Court) is that it is a decision for her and MPs. This decision of MPs takes into account, only, the referendum outcome. Secondly, without setting out fully and clearly what rights will be lost and with what consequences she expects for those affected the Prime Minister cannot rationally exercise her discretion to trigger Art 50.


The combination of both grounds makes any decision at this stage open to a challenge that it has been arrived at irrationally; and if challenged successfully, that it could be declared void by the High Court.


David Burrows

8 February 2017

© David Burrows, Paris 2017





Extract from Briefing Paper


  1. Types of referendum This Bill requires a referendum to be held on the question of the UK’s continued membership of the European Union (EU) before the end of 2017. It does not contain any requirement for the UK Government to implement the results of the referendum, nor set a time limit by which a vote to leave the EU should be implemented. Instead, this is a type of referendum known as pre-legislative or consultative, which enables the electorate to voice an opinion which then influences the Government in its policy decisions. The referendums held in Scotland, Wales and Northern Ireland in 1997 and 1998 are examples of this type, where opinion was tested before legislation was introduced. The UK does not have constitutional provisions which would require the results of a referendum to be implemented, unlike, for example, the Republic of Ireland, where the circumstances in which a binding referendum should be held are set out in its constitution. In contrast, the legislation which provided for the referendum held on AV in May 2011 would have implemented the new system of voting without further legislation, provided that the boundary changes also provided for in the Parliamentary Voting System and Constituency Act 2011 were also implemented. In the event, there was a substantial majority against any change. The 1975 referendum was held after the re-negotiated terms of the UK’s EC membership had been agreed by all EC Member States and the terms set out in a command paper and agreed by both Houses.64





Contents page of White Paper


  1. Providing certainty and clarity – We will provide certainty wherever we can as we approach the negotiations.
  2. Taking control of our own laws – We will take control of our own statute book and bring an end to the jurisdiction of the Court of Justice of the European Union in the UK.
  3. Strengthening the Union – We will secure a deal that works for the entire UK – for Scotland, Wales, Northern Ireland and all parts of England. We remain fully committed to the Belfast Agreement and its successors.
  4. Protecting our strong and historic ties with Ireland and maintaining the Common Travel Area – We will work to deliver a practical solution that allows for the maintenance of the Common Travel Area, whilst protecting the integrity of our immigration system and which protects our strong ties with Ireland.
  5. Controlling immigration – We will have control over the number of EU nationals coming to the UK.
  6. Securing rights for EU nationals in the UK, and UK nationals in the EU – We want to secure the status of EU citizens who are already living in the UK, and that of UK nationals in other Member States, as early as we can.
  7. Protecting workers’ rights – We will protect and enhance existing workers’ rights. 8. Ensuring free trade with European markets – We will forge a new strategic partnership with the EU, including a wide reaching, bold and ambitious free trade agreement, and will seek a mutually beneficial new customs agreement with the EU.
  8. Securing new trade agreements with other countries – We will forge ambitious free trade relationships across the world. 10. Ensuring the UK remains the best place for science and innovation – We will remain at the vanguard of science and innovation and will seek continued close collaboration with our European partners.
  9. Cooperating in the fight against crime and terrorism – We will continue to work with the EU to preserve European security, to fight terrorism, and to uphold justice across Europe.
  10. Delivering a smooth, orderly exit from the EU – We will seek a phased process of implementation, in which both the UK and the EU institutions and the remaining EU Member States prepare for the new arrangements that will exist between us.