This is the second and final part of this series; the first is available here.
7. What is the status of the UK during the negotiation process?
As discussed above, subject to application of paragraph 4, which deals with participation in discussion in the European Council and Council relating to the withdrawal process, the withdrawing State remains a Member State of the EU, with rights and obligations intact.
As regards the rights of the withdrawing State, certain interpretive difficulties may arise in any attempt to delineate the situations in which the withdrawing State may, and may not, be involved in European Council and Council decision-making. Once again, this is an area in relation to which the guidelines provided by the European Council may provide clarity. In practice it seems almost inevitable that the role and influence of the withdrawing State will inevitably diminish. It is unclear whether the State will have an interest in influencing the making of decisions at EU level which might well never concern it; and arguable that it is not legitimate to afford it such a role. The power of the argument against involvement will of course depend on the extent to which it is envisaged that the withdrawing State aspires to continue to have a relationship with the EU.
As regards obligations, the UK will continue to be bound by EU law rules until the withdrawal agreement enters into force. This includes new EU legislation adopted after Article 50 is triggered, but before the withdrawal agreement enters into force. While the UK is due to assume the Presidency of the Council in the second half of 2017, it is anticipated that alternative arrangements will be made in order to ensure the efficient functioning of the Union. The principle of sincere cooperation enshrined in Article 4(3) TEU would continue to apply, and there are suggestions that it might be used in relation to the conduct of the withdrawing State during the process of withdrawal.
8. How is the withdrawal agreement concluded?
Finally, there are significant uncertainties relating to the conclusion of the withdrawal agreement, both by the EU and the withdrawing State.
Let me begin with the position as regards the EU. The withdrawal agreement itself is negotiated as an EU external agreement, as is made clear by the reference to Article 218(3) in Article 50. Paragraph 2 provides that the agreement is to be concluded ‘on behalf of the Union by the Council acting by qualified majority after obtaining the consent of the European Parliament’. Thus, it is possible for an agreement to be reached without the approval of all 27 Member States; and, unlike in the case of accession, for the scope of the Union to be altered notwithstanding the lack of the unanimous consent of the Member States. Equally, it is possible for an agreement not to be concluded notwithstanding the fact that it is approved by the governments of all the Member States. No agreement can be concluded if a majority in the European Parliament vote against it. It is also possible, as discussed in e) above, that alongside any withdrawal agreement, there will be another agreement, or set of agreements, dealing with the future relationship between the withdrawing State and the Union. To the extent that any such agreements are mixed agreements, they require ratification by all Member States, a process which will inevitably slow down the conclusion of the negotiation process.
On the side of the UK, the withdrawal agreement would require ratification in Parliament, in accordance with the UK’s constitutional requirements.
How might these questions be settled?
The discussion so far indicates that many of the EU law questions relating to the process of withdrawal from the EU are unresolved. Nevertheless, given the uncertainty inherent in Article 50, it is contended here that it is possible, perhaps probable, that there will be litigation in relation to the process. There is the potential for such litigation to occur at both the national and the European level. It is difficult, at this stage, to predict the form which such litigation might take, but there are a range of claims which it is possible to envisage.
Claims may come before the European Court of Justice in the following ways. The most obvious basis for legal action will be in relation to the content and scope of any withdrawal agreement. Such an action might relate both to the procedures through which the withdrawal agreement was reached, and the substantive terms of any such agreement; and might come before the Court either directly in an Article 263 TFEU judicial review action, or indirectly, via a preliminary reference from a national court under Article 267 TFEU. It may, in addition, be possible to seek an advisory opinion from the Court via Article 218(11) TFEU as to whether the agreement is compatible with the Treaties. Actions may also be brought at earlier stages in the process, for example in relation to whether the negotiation process is compatible with EU law. As has been mentioned above, it is possible to envisage the making of claims against the withdrawing State, not only by the Commission under Articles 258 and 260 TFEU, but also, potentially, by the European Council and Council under Article 7 TEU.
There is already discussion of legal action in the UK on the basis of the conduct of the referendum campaign, and over the constitutionality of any decision to pull the Article 50 trigger. Such litigation is likely to raise questions relating to the interpretation of EU law (most obviously, in relation to the interpretation of Article 50, perhaps based on the points discussed above), which the UK courts may decide to refer to the Court of Justice. At each stage of the process, legal action is possible – for example in relation to the conduct of the negotiations, and of course, in relation to the scope and substantive content of the withdrawal agreement(s).
This paper suggests that, in order to avoid the risk of litigation, the rules of the process should be clarified via the guidelines to be provided by the European Council. So as to be able to fulfil this function, the guidelines must be provided prior to any decision by the UK to trigger A50, and should provide as much clarity as possible in relation to the key questions discussed above, including in particular in relation to the ability of the UK to rescind the notification process, the scope of the withdrawal agreement(s), the status of the UK during the withdrawal process, and the mechanisms through which the withdrawal agreement(s) may be concluded. It is recommended that the UK government be fully involved in the drawing up of these guidelines. It may, of course, be that agreement is impossible to attain, or that the European Council refuses to provide guidelines before the decision to trigger Article 50. In such circumstances, it may be that there is litigation in relation to the Article 50 process, with courts playing a key role in shaping the process of withdrawal.
A suggested way forward
It hardly needs to be said that this is a crisis situation for the European Union. The prospect of the withdrawal of the UK from the EU is fraught with economic and political risk. Article 50 is intended to provide for the orderly exit of States from the Union. Whether or not this goal is achieved will largely depend on the conduct of the withdrawing State and the process of negotiation. Nevertheless, the legal framework in which the negotiations take place is also significant, as it determines the parameters within which the range of political actors involved will frame their strategies. The text of Article 50 provides very few answers. Nevertheless it envisages the provision of guidelines by the European Council. These may operate as the vehicle through which the answers to the legal questions identified in this paper are developed. In order to be able to play this role, they should, in the wake of the referendum outcome, be provided in advance of any decision by the UK to trigger Article 50. And, to the extent that this is possible, they should, notwithstanding the wording of Article 50(4), be agreed in negotiation with the UK, in order to minimise the risk of what may prove to be complex litigation, across more than one jurisdiction, in relation to the conduct of the withdrawal process.
I have argued above for Article 50 to be interpreted in a way which ensures that the UK is best able to maintain a working relationship with the UK, and achieve a settlement in which the interests of citizens of the EU are best protected. This suggests that the European Council guidelines should provide not only for a withdrawal agreement, but also for an agreement which defines the future relationship between the UK and the EU. To the extent that this objective is not achievable within two years, the European Council should commit to extending the time period. Most importantly, it should be made clear it is possible for the UK to rescind its notification, together with any procedural steps to be taken in order to stop the process.
Once there is more clarity, the UK will be able to consider its response. The calls to refuse to pull the Article 50 trigger are increasing, with legal efforts within the UK directed to imposing pressure on Parliament, either as a result of the conduct of the referendum campaign, or a result of the rights affected by the withdrawal process, not to trigger Article 50. While this option might be constitutional as a matter of UK law, it would carry with it a multitude of social risks, furthering poisoning relationships between the political elite and the people, who may feel that the result of the referendum has been ignored.
It would be far better for Parliament to accede to the will of the people, and trigger Article 50; but only once the Article 50 process has been clarified; and it is argued here that this should be via European Council guidelines relating to the process of negotiation. Parliament has a role in scrutinising these guidelines, and in providing full guidance to the government and the people in relation to the substantive content and scope of the negotiations, the negotiation timetable, and the steps to be taken in relation to the conclusion and ratification of the resulting agreement(s).
As has been argued above, it should be made clear that it is possible for the UK to rescind the Article 50 notification. The European Council should commit to negotiations with the UK in relation not only to a narrow withdrawal agreement, but also to a broader agreement on the future relationship between the UK and the EU. It is only if these two conditions are met – and it may be possible for the UK to exert not only political but also legal pressure on the European Council in relation to the content of the guidelines – that it is possible to envisage a legitimate outcome to this crisis.
The clarification of the uncertainty surrounding the Article 50 process will enable the UK to make an informed decision in relation to the pulling of the Article 50 trigger. The UK government must then work on its negotiating strategy, and seek to reach an agreement with the EU27 which deals with withdrawal and the future relationship between the UK and the EU. It is only during the process of negotiation that it will become clear what leaving the EU will actually entail. There will, presumably, be a range of difficult decisions, for example in relation to the UK’s desire to control immigration, and to retain access to the single market (and we will all learn a lot about the operation of the EEA, and Switzerland’s relationship with the EU); and about the acquired rights of EU citizens in the UK, and UK citizens in the EU. In the time period in which negotiations will occur, there will no doubt be significant economic and political change within both the EU and the UK. Towards the end of the negotiation period, it will be possible for the UK to make an informed choice; either a) to rescind its notification and remain within the EU, b) to accept the negotiated deal, or c) to exit the EU without a deal. That decision will be for the UK, in accordance with its constitutional requirements. Parliament will of course be involved, and consideration will no doubt be given to allowing the people to have a further say, either via a general election or indeed a second referendum.
The process of withdrawal is not going to be easy. The EU law framework surrounding the operation is very unclear, with the provision of guidelines by the European Council representing a key moment in which it is possible to contribute towards the legitimacy of that process. This paper offers a number of recommendations. It is to be hoped that it prompts careful consideration of the options ahead, so that it is possible to arrive at a legitimate outcome, in which the interests of citizens of the EU are, as far as possible protected.
 Nationals of the withdrawing State will, in principle, retain their positions in the EU institutions pending the entry into force of the withdrawal agreement. It is interesting in this regard that there seem to be no plans to replace Lord Hill, the UK Commissioner who resigned in the wake of the referendum result.
 It should noted that there may be complications in relation to the enforcement of EU law against the withdrawing Member State; whether before the Court of Justice, under Article 258-260, or before the national courts. See further below.
 House of Lords European Committee Report, n7 above at .
 See Hillion, n4 above at 139-40.
 On the possibility of a turf war between the EU institutions, see Duff, n4 above.
 See Lazowski, n4 above at 528.
 See https://www.theguardian.com/law/2016/jul/03/parliament-must-decide-whether-or-not-to-leave-the-eu-say-lawyers and http://www.theguardian.com/politics/2016/jul/05/deadline-approaches-government-response-brexit-legal-challenge-article-50.
 See also R Ekins, ‘The Legitimacy of the Brexit Referendum’, UK Constitutional Law Association Blog, available at https://ukconstitutionallaw.org/2016/06/29/richard-ekins-the-legitimacy-of-the-brexit-referendum/.