Key points

  • The UK will need to make use of the Article 50 process to bring about Brexit. 
  • The process would be easy for an exiting state that does not require an extensive new relationship with the EU, but there are serious difficulties and uncertainties for the UK (which is looking for a new relationship).  
  • There is considerable uncertainty about key aspects of the Article 50 process (both for the exiting state and for the remaining bloc) including the scope of any withdrawal agreement and the simplified process for its adoption (which is based on a qualified majority, rather than unanimity, in the European Council/amongst the 27 states). Interpretation is ultimately a matter for the CJEU. 
  • Once the UK gives notice, it has no express right under Article 50 to control unilaterally the date when exit from the EU takes effect (BID) or to make exit conditional, for example on concluding a withdrawal agreement. BID can be controlled by agreement with Member States via a withdrawal agreement or using the delay mechanism.
  • The UK and Member States/the EU institutions have not found common ground on whether and how a smooth transition from EU membership to the new relationship can be agreed and implemented.

Can the UK leave the EU without invoking Article 50?

Article 50 TEU[1] sets out the legal process by which a Member State can withdraw from the EU: it outlines the procedural requirements but it is not substantive.

Some have suggested that there are alternative ways to withdraw from the EU, including under principles of international law applicable to international treaties – the arguments put forward have largely been dismissed. In a report by the House of Lords’ European Union Committee[2], witnesses argued that Article 50 was the only option available:

[…] it has been suggested that the UK could withdraw from the EU without reference to Article 50, for example by repealing the European Communities Act 1972, which gives domestic effect to EU law. We asked our witnesses whether this would be possible. Both told us that Article 50 provided the only means of withdrawing from the EU consistent with the UK’s obligations under international law.[3]"

Prior to the introduction of Article 50 (under the Lisbon Treaty) there was no Treaty basis for a Member State to leave the EU. Article 50 is significant in that it provides a legal mechanism for a Member State to exit the EU: 

  • unilaterally – see question 3 below; 
  • without having to secure amendments to the Treaties; 
  • within 2 years; and
  • with a simplified process to facilitate a withdrawal agreement. 

The Article 50 process would work well for an exiting state that did not wish to replace EU membership with a new relationship with the EU. The realities and practicalities for the UK are much more difficult and challenging. Article 50 is simplistic and leaves many key procedural issues unclear or unanswered. 

Who can invoke Article 50?

Article 50 TEU states that:  

  1. Any Member State may decide to withdraw from the Union in accordance with its own constitutional requirements.
  2. A Member State which decides to withdraw shall notify the European Council of its intention.

It is clear that only the exiting Member State can invoke Article 50 (by giving notice to the European Council of its intention to withdraw from the EU).

There is some uncertainty (and several legal challenges) about the UK’s domestic constitutional requirements – [see report 2 that deals with the legal status of the UK’s referendum on EU membership and report 3 that looks at the question of whether parliamentary approval is required before the UK government can trigger Article 50].

Does the UK require the consent of the EU to leave?

Notice of withdrawal is unilateral: consent of the EU Member States, European Parliament, or European Commission is not required[4]. A member state can achieve exit simply by giving notice and waiting 2 years (see question 8 below).

In practice, however, an exiting state would wish to secure at least an agreement on issues arising on withdrawal (see question 5 below). The position of the UK is much more difficult as it also wishes to negotiate a new relationship with the EU.

Is the UK entitled to decide when to give notice under Article 50?

Immediately after the referendum result, the EU institutions’ leaders and certain Member States signaled that the UK should give notice and commence the withdrawal process as soon as possible -

"We now expect the United Kingdom government to give effect to this decision of the British people as soon as possible, however painful that process may be […] We stand ready to launch negotiations swiftly with the United Kingdom regarding the terms and conditions of its withdrawal from the European Union." Tusk

"[…] the will of the British people must now be put into effect as quickly as possible. Under Article 50 of the EU Treaty the UK must leave the European Union within two years at the latest." Juncker

However, Article 50 does not specify when notice must be given. A pre-referendum European Parliament Research Briefing states that "[t]he timing of this notification is entirely in the hand of the Member State concerned"[5].

It does now seem that the EU and Member States are resigned to the fact that the UK government can decide when to trigger Aricle 50 and that it will take some time post-referendum before giving notice to the European Council.

What is the process under Article 50 for negotiating and concluding a withdrawal agreement?

Once notice has been given:

"The European Council (without the participation of the Member State concerned) then provides guidelines for the negotiations between the EU and the state concerned, with the aim of concluding an agreement setting out concrete withdrawal arrangements. […]The Union and the Member State wishing to withdraw have a time-frame of two years to agree on these arrangements.[6]"

The UK’s status and role in the negotiations is described in a House of Lords EU Committee briefing:

"Under Article 50 the parties to the negotiation would be the European Union and the withdrawing Member State. As the other party to the negotiations, the UK would be treated as a non-EU State for the purpose of Article 50. It would not therefore participate in discussions concerning the withdrawal negotiations in the European Council or the Council.[7]"

However, MEPs from the withdrawing Member State may be able to participate in the discussions:

"It should be noted that whilst, under Article 50(4) TEU, the member of the European Council or of the Council representing the withdrawing Member State does not participate in the discussions of the two institutions or in decisions concerning the withdrawal, no similar provision exists for Members of the European Parliament (MEPs) elected in the withdrawing Member State.This has led some to conclude that the Treaties therefore do not prevent MEPs elected in the Member State in question from participating either in debates in the Parliament and in its committees, or from voting on Parliament's motion to consent to the withdrawal agreement, given the role of MEPs as representing the Union's citizens as a whole and not only those of the Member State in which they were elected.[8]"

The role of the European Commission in the negotiating process:

"The role of the European Commission in the withdrawal procedure is not entirely clear in the Treaties. According to Article 218(3) TFEU, the European Commission would make recommendations to the Council to open negotiations with the withdrawing state. As a general rule, the Commission negotiates agreements with third countries on behalf of the EU, but Article 218(3) leaves it open for the Council to nominate a different Union negotiator.[9]"

Michel Barnier has been appointed as the lead Brexit negotiator by the European Commission – he will report directly to Juncker.

Article 50 provides/envisages a simplified/straight forward process for a withdrawal agreement. In particular, this process does not require unanimity/the agreement of all 27 remaining states.

A super qualified majority in the Council – without the withdrawing Member State – is sufficient to conclude the agreement. Article 238(3)(b) TFEU provides that qualified majority in this case is at least 72% of the members of the Council, comprising at least 65% of the population of the Member States (excluding the withdrawing Member State).The Council of the European Union must obtain the European Parliament’s consent before concluding the agreement.[10]

What is the potential scope of the withdrawal agreement? How does the Article 50 process relate to the UK-EU negotiation of a new (post-Brexit) relationship/free trade agreement?

Article 50(2) states that "[…] the Union shall negotiate and conclude an agreement with that State, setting out the arrangements for its withdrawal, taking account of the framework for its future relationship with the Union. […]".

This sounds straight forward on first reading, but raises legal questions and uncertainty of considerable importance to the UK.

The withdrawal agreement will clearly set out the arrangements for the UK’s withdrawal. One can envisage many issues that will fall within this description – for example the withdrawal arrangements for the move of EU institutions in the UK, such as the EBA, to other states, for the UK’s budget contribution, rebate and the receipt of EU funding by UK entities and for the UK members of the European Parliament, judges at the CJEU and the UK Commissioner.

For the UK, however, the key question is to what extent the withdrawal agreement can regulate the EU/UK relationship post-Brexit. This would be very attractive to the UK because such matters could be agreed under the simplified process, without having to get the agreement of every Member State and, critically, the post-Brexit arrangements could take effect at withdrawal/BID. This would avoid any ‘void’ period arising in EU/UK relations between BID and whenever a new relationship is finally negotiated and brought into effect.

The EU has generally seen the negotiation of the withdrawal agreement, and perhaps the withdrawal itself, as separate from, and pre-conditions for, the negotiation of a new relationship. This position was reiterated in the European Parliament resolution of 28 June 2016: "[…] any new relationship between the UK and the EU may not be agreed before the conclusion of the withdrawal agreement". A pre-referendum European Parliament Research Briefing[11] on the Article 50 process describes the withdrawal agreement as "merely declaratory" and states that the "withdrawal takes place even if an agreement is not concluded (Art. 50(3) TEU)" (see question 8 below).

In the UK, there has been much greater emphasis on the reference in Article 50 to the withdrawal agreement setting out the arrangements for the withdrawal, ‘taking account of the framework for its future relationship with the Union.’ A House of Commons Library Briefing Paper[12] notes:

"It is not clear from Article 50 TEU whether all the arrangements for the withdrawing State’s future relationship with the EU would be included in the withdrawal agreement, or require the negotiation of a separate agreement with the EU. Article 50(2) TEU refers only to negotiating and concluding arrangements for withdrawal, ‘taking account of the framework for [the exiting State’s] future relationship with the Union’."

Interpretation and analysis of the Treaty text was discussed at a House of Lords EU Committee hearing. Sir David Edward QC highlighted the linguistic differences between the English, French, and German versions of Article 50:

"The English text envisages that "the Union shall negotiate and conclude an agreement with the withdrawing state setting out the arrangements for its withdrawal and taking account of the framework for its future relationship with the Union". That is broadly the same as the French text. However, there is a difference in the German text, which I translate as follows: that they will "conclude the agreement whereby the framework for future relations will be taken into consideration"—or it might even be "will have been taken into consideration". In other words, I think the German text envisages that the structure of future relations will already have been established at the point when withdrawal takes place."

It seems very unlikely that the UK could persuade the EU that the entirety of the ‘new relationship’ should be negotiated and included within the withdrawal agreement and would be coverd by the ‘simplified’ Article 50 process. The new relationship is potentially broad, complicated and detailed – covering at least as much as the 120 and more agreements that make up the EU-Swiss arrangement. It would seem to be difficult to argue, say before the CJEU, that the wording of Article 50 permits this - it only talks of ‘taking account’ of the ‘framework for’ the future relationship. There must also be limits on the use of the simplified process in Article 50 bearing in mind that the new relationship will stray into areas of Member State competence where agreements are subject to ratification by Member States (see question 7 below).

A more realistic issue/question may be the extent to which, bearing in mind the framework reference, the withdrawal agreement may be used to avoid or mitigate a complete break (or ‘void’) in EU-UK relations at BID.

This might be achieved, for example, by a staggered programe for Brexit implementation, by a delay to BID beyond the 2 year period (see question 8 below) and/or transtional type provisions to apply after BID for a given period or until the new relationship comes into effect. Businesses in the UK and the EU have a strong interest in a smoth transition, but the the governments of the UK/other states and the EU institutions have not yet found an agreed legal basis to deliver this (see RegZone report Brexit (5): negotiating Brexit and the danger of a bad transition).

Could there be procedural complications?

See question 8 below in relation to complications relating to the timing of BID.

There are also potential complications relating to the simplified process under Article 50 for the conclusion of the withdrawal agreement. Professor Wyatt QC, giving evidence before a House of Lords EU Committee[13] argued that "[i]f the agreement is deemed to be ‘mixed’ (where Member State as well as EU competences are engaged), it will have to be ratified by the Member States as well". See RegZone report Brexit (8): Bilateral and bespoke – a UK-EU deal? for further information on this topic.

If any agreements (whether the withdrawal agreement or other agreements e.g. those relating to the new relationship) are subject to Member State ratification, the question may then arise as to whether such agreements can be given ‘provisional application’. For example, the European Commission formally proposed the provisional application of the EU-Canada Free Trade Agreement to the Council of the EU in early July 2016, pending Member State approval. Following a decision of the Council, it will be possible to provisionally apply the agreement. For further analysis of this topic, see RegZone report Brexit (8): Bilateral and bespoke – a UK-EU deal?

A pre-referendum House of Commons Library Briefing Paper states that:

"The EU Council tends to wait for ratification to be completed in all Member States before concluding (ratifying) a mixed agreement on behalf of the EU. But because of the length of time this can take, the EU has taken to introducing interim agreements which provisionally apply elements or all of the agreement."

The legal basis for these provisional agreements is Article 207 TFEU. Provisional application requires the EU and Member States to sign the agreement: "[s]ignature indicates an undertaking not to frustrate the object and purpose of the agreement before its entry into force (Article 18 of the 1969 Vienna Convention on the Law of Treaties)."

Finally, the withdrawal agreement’s legal status means that it will be vulnerable to challenge before the CJEU. A European Parliament Briefing explains the status of the withdrawal agreement: "unlike accession treaties, the withdrawal agreement is not primary EU law, since it is concluded between the EU and the withdrawing state and not between the latter and the rest of the Member States.[14]" Given its legal status as an international agreement, it may be subject to legal challenge before the Court of Justice of the European Union: "The Council decision to conclude the agreement could, for instance, be challenged before the CJEU through an action for annulment (Article 263 TFEU).[15]"

When does Brexit implementation date (‘BID’) occur?

Article 50(3): " The Treaties shall cease to apply to the State in question from the date of entry into force of the withdrawal agreement or, failing that, two years after the notification referred to in paragraph 2, unless the European Council, in agreement with the Member State concerned, unanimously decides to extend this period."

Article 50 envisages that a withdrawal agreement will be concluded and that this agreement will itself regulate when it comes into effect/the date of BID. Article 50 does not address the question of whether the simplified process can be used to stipulate, within a withdrawal agreement concluded within 2 years, a BID after the 2-year anniversary period. Arguably, that might require unanimity within the European Coucil.

As to the extension of the two-year period – oral evidence before the House of Lords EU Committee hearing:

"The two-year period can be extended by the European Council, acting unanimously. There is no limit to the length of the extension, nor to the number of times an extension can be agreed.[16]"

If at the end of the 2-year period, no withdrawal agreement has been concludued and no extension is unanimously agreed, Brexit is triggered automatically at that point, and the EU treaties and EU law cease to apply to the UK. As noted above, the conclusion of a withdrawal agreement is not a pre-requisite to Brexit/BID.

Could the UK, after giving notice under Article 50, prevent or delay BID by unilaterally withdrawing its notice to withdraw?

There are several scenarios in which the UK might consider withdrawing its Article 50 notice (after it was given but before it took effect). The UK might have a change of heart and decide it wishes to remain in the EU (for example if the EU itself was to commit to reform). Alternatively, the UK might have more tactical/procedural reasons, for example, if it wished to delay and control the date of BID without having to obtain unanimous agreement from all Member States.

The European Parliament Research Briefing covers the issue of withdrawing notice:

"The question could be posed as to whether – once a Member State has notified the European Council of its intention to withdraw from the EU, and a withdrawal agreement has been negotiated – it can, depending on the results of the negotiations, unilaterally revoke its notification and suspend the withdrawal procedure. Most commentators argue that this is impossible or at least doubtful, from a legal point of viewIndeed Article 50 TEU does not expressly provide for the revocation of a notice of withdrawal and establishes that, once opened, the withdrawal process ends either within two years or later, if this deadline is extended by agreement.[17]"

This is in contrast to evidence given to the House of Lords EU Committee hearing:

"We asked our witnesses whether it was possible to reverse a decision to withdraw. Both agreed that a Member State could legally reverse a decision to withdraw from the EU at any point before the date on which the withdrawal agreement took effectOnce the withdrawal agreement had taken effect, however, withdrawal was final. […]Both witnesses drew a distinction, however, between the law and the politics of such a scenario.[18]"

There is, however, no express provision in Article 50 permitting notice to be withdrawn unilaterally and the question could only ultimately be determined by the CJEU. In the case of a genuine change of heart, one might expect unanimous support from the EU Member States and institutions, but tactical withdrawal of its notice by the UK is likely to be resisted and would hang on the eventual decision of the CJEU.

To what extent will the remaining states need to revise EU arrangements post BID?

The European Parliament Research Briefing[19] addresses this issue:

"[…] the withdrawal of a Member State does not require ratification by the remaining Member States – Article 50(1) TEU mentions (in a declaratory way) only the decision of the withdrawing state, in accordance with its constitutional requirements. However, any Treaty changes or international agreements (such as a free trade agreement) that might be necessary as a consequence of the withdrawal agreement would need to be ratified by the remaining Member States in accordance with Article 48 TEU. At the very least, Article 52 TEU on the territorial scope of the Treaties, which lists the Member States, would need to be amended, and Protocols concerning the withdrawing Member State revised or repealed."

Brexit will clearly have various consequences for the remaining EU Member States, most obviously in terms of budget contributions, and it may well trigger other changes. Some form of revision agreement amongst the continuing 27 states is therefore to be expected.

Annex A

Article 50 – Treaty on European Union (TEU)

  1. Any Member State may decide to withdraw from the Union in accordance with its own constitutional requirements.
  2. A Member State which decides to withdraw shall notify the European Council of its intention. In the light of the guidelines provided by the European Council, the Union shall negotiate and conclude an agreement with that State, setting out the arrangements for its withdrawal, taking account of the framework for its future relationship with the Union. That agreement shall be negotiated in accordance with Article 218(3) of the Treaty on the Functioning of the European Union. It shall be concluded on behalf of the Union by the Council, acting by a qualified majority, after obtaining the consent of the European Parliament.
  3. The Treaties shall cease to apply to the State in question from the date of entry into force of the withdrawal agreement or, failing that, two years after the notification referred to in paragraph 2, unless the European Council, in agreement with the Member State concerned, unanimously decides to extend this period.
  4. For the purposes of paragraphs 2 and 3, the member of the European Council or of the Council representing the withdrawing Member State shall not participate in the discussions of the European Council or Council or in decisions concerning it. A qualified majority shall be defined in accordance with Article 238(3)(b) of the Treaty on the Functioning of the European Union.
  5. If a State which has withdrawn from the Union asks to rejoin, its request shall be subject to the procedure referred to in Article 49.

Annex B

Article 48 – Treaty on European Union (TEU)

  1. The Treaties may be amended in accordance with an ordinary revision procedure. They may also be amended in accordance with simplified revision procedures.

Ordinary revision procedure

  1. The Government of any Member State, the European Parliament or the Commission may submit to the Council proposals for the amendment of the Treaties. These proposals may, inter alia, serve either to increase or to reduce the competences conferred on the Union in the Treaties. These proposals shall be submitted to the European Council by the Council and the national Parliaments shall be notified.
  2. If the European Council, after consulting the European Parliament and the Commission, adopts by a simple majority a decision in favour of examining the proposed amendments, the President of the European Council shall convene a Convention composed of representatives of the national Parliaments, of the Heads of State or Government of the Member States, of the European Parliament and of the Commission. The European Central Bank shall also be consulted in the case of institutional changes in the monetary area. The Convention shall examine the proposals for amendments and shall adopt by consensus a recommendation to a conference of representatives of the governments of the Member States as provided for in paragraph 4.

The European Council may decide by a simple majority, after obtaining the consent of the European Parliament, not to convene a Convention should this not be justified by the extent of the proposed amendments. In the latter case, the European Council shall define the terms of reference for a conference of representatives of the governments of the Member States.

  1. A conference of representatives of the governments of the Member States shall be convened by the President of the Council for the purpose of determining by common accord the amendments to be made to the Treaties.

The amendments shall enter into force after being ratified by all the Member States in accordance with their respective constitutional requirements.

  1. If, two years after the signature of a treaty amending the Treaties, four fifths of the Member States have ratified it and one or more Member States have encountered difficulties in proceeding with ratification, the matter shall be referred to the European Council.

Simplified revision procedures

  1. The Government of any Member State, the European Parliament or the Commission may submit to the European Council proposals for revising all or part of the provisions of Part Three of the Treaty on the Functioning of the European Union relating to the internal policies and action of the Union.

The European Council may adopt a decision amending all or part of the provisions of Part Three of the Treaty on the Functioning of the European Union. The European Council shall act by unanimity after consulting the European Parliament and the Commission, and the European Central Bank in the case of institutional changes in the monetary area. That decision shall not enter into force until it is approved by the Member States in accordance with their respective constitutional requirements.

The decision referred to in the second subparagraph shall not increase the competences conferred on the Union in the Treaties.

  1. Where the Treaty on the Functioning of the European Union or Title V of this Treaty provides for the Council to act by unanimity in a given area or case, the European Council may adopt a decision authorising the Council to act by a qualified majority in that area or in that case. This subparagraph shall not apply to decisions with military implications or those in the area of defence.

Where the Treaty on the Functioning of the European Union provides for legislative acts to be adopted by the Council in accordance with a special legislative procedure, the European Council may adopt a decision allowing for the adoption of such acts in accordance with the ordinary legislative procedure.

Any initiative taken by the European Council on the basis of the first or the second subparagraph shall be notified to the national Parliaments. If a national Parliament makes known its opposition within six months of the date of such notification, the decision referred to in the first or the second subparagraph shall not be adopted. In the absence of opposition, the European Council may adopt the decision.

For the adoption of the decisions referred to in the first and second subparagraphs, the European Council shall act by unanimity after obtaining the consent of the European Parliament, which shall be given by a majority of its component members.