Brexit Institute News

The Failure of the EU-UK Legal Guarantees to Save the Withdrawal Agreement

The Failure of the EU-UK Legal Guarantees to Save the Withdrawal Agreement

Chloé Papazian (DCU Brexit Institute)

Exactly three months have passed since the UK Prime Minister Theresa May postponed the vote by the House of Commons on the withdrawal agreement on 11 December 2018. The following day, she embarked upon a European tour to obtain clarifications on the status of the Irish backstop and possibly legal re-assurances from the EU regarding the temporary character of the backstop.

Since then a political chaos has prevailed in Westminster. Numerous twists and turns have characterised the UK internal process of approval of the withdrawal agreement. On Monday 11 March, however, on the eve of the meaningful vote, the President of the European Commission Jean-Claude Juncker and the UK Prime Minister appeared together at a press conference with jointly agreed legal guarantees in their hands. After three months, the long-sought agreement between the EU and the UK bringing legal clarifications concerning the intended temporary application of the backstop might have surprised and brought some lights of hope. As the negotiations between the EU and the UK appeared in the deadlock on Monday morning suggesting a heavy rejection of the withdrawal agreement during the meaningful vote on Tuesday, the atmosphere changed progressively during the day. After some more positive talks, the gridlock eventually ended permitting Theresa May to fly over to the European Parliament in Strasbourg to finalise and sign off the revised package. At the joint press conference with Mr Juncker, the UK Prime Minister revealed the three instruments that had just been concluded by both parties.

The EU-UK Legal Clarifications and Guarantees

  • The first document constitutes a Joint Interpretative Instrument related to the withdrawal agreement specifying that the EU cannot act with the objective of applying the Irish backstop indefinitely without running the risk of breaching its best endeavours and good faith duties enshrined in Article 2.1 of the Protocol on Ireland/Northern Ireland (the ‘Protocol’) which lays down the so-called Irish backstop. Should the EU fail to comply with its obligations, the UK could bring a dispute before the arbitral tribunal as conceived by the withdrawal agreement. Ultimately, should the arbitration decide in favour of the UK and should the EU fail to comply with the tribunal’s ruling, the UK could suspend the application of all or parts of the Protocol, including the backstop. The Joint Interpretative Instrument also contains different legal commitments by both parties to speedily go back to the negotiating table after the UK exit and find alternative arrangements by the end of the transition period that would render the implementation of the backstop unnecessary.
  • The second document is a Joint EU-UK Statement supplementing the Political Declaration concluded on 25 November by both parties, a non-binding instrument attached to the withdrawal agreement. Under such statement, the EU27 and the UK reiterated their “shared ambition” to enhance and accelerate the process of negotiating and putting into effect a future partnership before the end of the transition period on 31 December 2020. For this purpose, they have agreed a series of measures included in the Joint Interpretative Instrument. Of particular importance is the “firm commitment” by both sides to start the formal negotiations immediately after the UK’s exit from the EU, as well as the corresponding establishment at the outset of these negotiations of a “specific negotiating track.” Such track will focus on the development of facilitative arrangements and technologies that would potentially supersede the backstop solution by the end of December 2020.
  • The third document corresponds to a UK Unilateral Declaration that the President of the European Commission initially opposed. The EU subsequently authorised the publication of such declaration which, nevertheless, as a unilateral instrument, does not bind the EU27. According to the UK-only declaration, nothing would prevent the UK Government from launching a procedure that could ultimately enable the UK to cease to apply their obligations under the Protocol should the EU fail to act in good faith and with its best endeavours to find alternative arrangements to replace the Irish backstop.

The EU has gone quite far in what it could concede to the UK without undermining the significance of the backstop – the insurance policy against the risk of the reinstallation of a hard border on the island of Ireland. It is not the first time that the EU has recourse to instruments of international law clarifying and interpreting provisions of a legally binding EU act to assist the national ratification. Such instruments which often take the form of legally binding treaty interpretations offer explanations on how the EU and its Member States should understand and apply the provisions encompassed in the EU act at stake. In 2009, the EU made use of such device to rescue the Treaty of Lisbon and permit its ratification by Ireland after a first referendum had voted the Treaty down. More recently, in 2016, the EU issued a legal text providing guarantees to the Netherlands on the association agreement between the EU and Ukraine. The text followed a rejection by Dutch voters in a non-binding referendum of the EU-Ukraine agreement.

Importantly, however, these international treaty interpretations must not contradict or add to the rights and obligations enshrined in the EU act concerned. Such legal constraint is precisely the justification of the little concessions the EU could offer. Pivotal for the conclusion of the withdrawal agreement between the EU and the UK was the Irish backstop solution which aims at avoiding the re-instauration of infrastructures, as well as customs and regulatory checks at the ‘invisible’ border between the North and the South of the island of Ireland. Hence, any guarantee, clarificatory provision or reassurance from the EU could not undermine or reduce the ‘effet utile’ of the backstop. This constraint constitutes the reason why the legal clarifications and guarantees secured by Theresa May clearly fall short of the unilateral exit mechanism or the clear time limit attached to the backstop the UK Government originally sought from the EU.

As a result, the hopes brought by the “meaningful guarantees”, according to the words of Jean-Claude Juncker, included in the Joint Interpretative Instrument faded away almost immediately after the revised package’s publication. Tuesday 12 of March which was supposed to be “the day” as the UK Prime Minister told her Cabinet initiated with a series of negative reactions regarding the EU-UK legal clarifications and re-assurances on the Protocol.

The shadow Brexit Secretary, Keir Starmer, for instance, said that the overnight announcement of legal guarantees had changed nothing. The lawyers of the European Research Group chaired by the Eurosceptic MP Bill Cash issued a similar statement signed by eight Brexiteer lawyers, notably the former Brexit secretary Dominic Raab and Nigel Dodds, the leader of the Democratic Unionist Party within the House of Commons. They declared in the statement that the legal assurances which the UK Government obtained from the EU did not “materially change the position the UK would find itself if it were to ratify the withdrawal agreement.” It is, however, the legal opinion of the UK Attorney General, Geoffrey Cox, published by the UK Government that gave the final blow to the already agonising withdrawal agreement.

The Legal Opinion of the Attorney General

At the outset of the document, Geoffrey Cox adopts a rather positive stance. The Joint Interpretative Instrument and the Unilateral Declaration provide “useful clarifications”, “amplified obligations” and “some new obligations” enhancing the rights of the UK in the event of a breach of the good faith and best endeavours obligations by the EU. The legal opinion, however, concludes in clear-cut terms: should a satisfactory subsequent agreement replacing the Protocol not be concluded because of “intractable differences” between the two Parties, the UK would risk having “no internationally lawful means of exiting the Protocol’s arrangements, save by agreement.”

Let us delve into the opinion of Mr Cox to better understand the improvements brought by the EU-UK legal guarantees and the remaining legal risk(s).

Throughout his legal advice which he presented before the House of Commons yesterday afternoon, Geoffrey Cox focused on two instruments only, namely the Joint Interpretative Instrument and the UK Unilateral Declaration. He underscored that while the Joint Instrument has been accepted and concluded by both Parties and hence constitutes an “authentic interpretation” of the withdrawal agreement, the Unilateral Declaration has not been accepted by the EU and thus does not bind the EU. The latter instrument may nonetheless be viewed as an “interpretative document”: in the words of the UK Attorney General, “it will be lodged with the depository of the Withdrawal Agreement and form part of the context of the Treaty.”

In a previous blog, I outlined the first legal opinion provided by the Attorney General to the UK Government published last December. In this first legal opinion, Geoffrey Cox singled out three aspects inherent to the Protocol permitting to assert that it is not in the best interests of the EU to apply the backstop solution for an indefinite period. Article 50 TEU, on which the withdrawal agreement rests, is not designed to fix the permanent arrangements between the EU and the UK. Hence, should the backstop solution become permanent, the UK could bring a dispute challenging the uncomfortable legal basis on which the Irish backstop lies. Moreover, the EU may be unwilling to grant to one part of a country (eg Northern Ireland) that exited the EU Single Market full access to the EU market for goods, and the EU Customs Union. In addition, as the UK financial contributions to the EU will cease after the transition period, the EU may be particularly reluctant to continue applying for a long-term period the Irish backstop plan enabling Northern Ireland to stay within parts of the EU Single Market. In other words, according to the Attorney General, the EU will likely wish “a clear and early end to the backstop” not only to avoid complex administrative and legal arrangements but also to avert a potential legal challenge by the UK Government.

The first legal opinion of the Attorney General, nevertheless, pinpointed one issue which became the centre of the MPs’ opposition to the withdrawal agreement. The crux of the problem related to the situation in which a partnership agreement between the EU and the UK superseding the backstop solution could not be agreed due to either irreconcilable differences between the two sides or to the EU failure to act in accordance with its duties of good faith and best endeavours. In such situation, as stated by Mr Cox, the Protocol could endure indefinitely with “no obvious room” for its termination. Particularly, the Protocol does not offer a legal means that could compel the EU to reach and conclude a superseding agreement. The EU-UK legal clarifications and guarantees aim to address such shortfalls. Throughout the two instruments he analysed, Geoffrey Cox identified three major elements that clarified and reinforced the rights of the UK should the EU fail to comply with its duties of good faith and best endeavours as enshrined in Article 184 of the withdrawal agreement, Article 2.1 of the Protocol and Paragraph 138 of the Political Declaration.

  • Legal operational commitments to conclude a superseding agreement: First, in various paragraphs of the Joint Instrument, the EU and the UK reiterated their commitments to deploy their best efforts and work speedily and diligently following the UK exit from the EU to find alternative arrangements before 31 December 2020. This would render the application of the backstop unnecessary (paragraphs 5 and 6 of the Joint Interpretative Instrument). The negotiating taskforce must particularly focus on comprehensive customs cooperation arrangements, facilitative arrangements and technologies that would guarantee an invisible border on the island of Ireland. For this purpose, the taskforce would rely on a specific negotiating track established immediately after the UK withdrawal (paragraph 7). The track would aim to replace the UK customs and regulatory alignment in goods with the EU envisaged in the Protocol with alternative arrangements. Most importantly, the EU and the UK jointly acknowledged that the alternative arrangements intended to replace the backstop are not required to replicate the provisions of the Protocol in any respect (paragraph 10 of the Joint Interpretative Instrument).
  • Legal recognition of the EU’s potential breach of its obligations under the Protocol: Second, as emphasised by the UK Attorney General, the Joint Interpretative Instrument acknowledged that the EU could be found in violation of its duties of good faith and best endeavours by systematically refusing to take into consideration adverse proposals or interests (paragraph 4 of the Joint Interpretative Instrument). According to Mr Cox, should the UK Government be sufficiently organised and prepared to maintain the urgent pace of negotiations, it could legally challenge the EU behaviour by proving that the EU27 has failed to respond to the UK propositions or has acted with “unjustified delay.”
  • Legal procedural rights to bring a challenge before the arbitral tribunal: Third, the Joint Interpretative Instrument officially gives the UK the right to dispute the EU delayed action or inaction before the arbitral tribunal that would be established immediately after the UK withdrawal from the EU. This procedural right could ultimately lead to a suspension of the application of the Protocol, including the backstop until the arbitral tribunal determines that the EU has ceased to act with bad faith or in breach of its best endeavour duties.

Hence, according to the UK Attorney General, the EU-UK revised package introduces clarificatory provisions, amplified obligations and some new obligations that significantly facilitate the enforcement of the UK rights in the event of an EU failure to act in accordance with its good faith and best endeavour obligations. In such situation – and in this situation only – the legal clarifications and guarantees “reduce the risk that the UK could be indefinitely and involuntarily detained within the Protocol’s provisions” (paragraph 17 of the Attorney General’s legal opinion).

Yet, the legal re-assurances fail to address another potential scenario: the one in which the EU’s and the UK’s irreconcilable differences would not permit to reach a superseding agreement. Indeed, although it is neither in the interests of the UK nor of the EU to apply the backstop indefinitely, the risk remained to see the UK being trapped, due to ‘intractable differences’ between the two sides in a ‘temporary’ customs union with the EU from which it could not unilaterally withdraw. As the EU and the UK constantly repeated, the Irish backstop would apply until and unless the EU and the UK conclude an agreement that would replace the backstop. Should the negotiations fail and should such agreement not be found despite the good faith of both Parties, the temporary backstop solution may end up becoming a permanent solution. Here one might see all the paradox inherent to the Irish backstop: designed as a solution having a temporary legal status only, its application would be triggered not only in the situation where the negotiations would last longer than the transition period but also in the case of a failure of the negotiations.


The ‘meaningful guarantees’ have therefore not sufficed to win the favour of the hardliner Tory Brexiteers, the DUP and the Labour MPs during yesterday evening’s meaningful vote. The UK Prime Minister suffered a second humiliating defeat as the withdrawal agreement was rejected by 149 votes.  Seventeen days before the UK exit from the EU, one is still wondering where the next step of the Brexit saga will bring us. Today, the House of Commons will vote on the UK Government’s motion to block a no-deal exit on March 29. A positive vote will be more than welcomed following the declarations of the President of the European Council, Donald Tusk, immediately after the meaningful vote yesterday, as well as the publication today of the UK Government’s tariff plans in a no-deal scenario which will considerably increase the prices paid by consumers on numerous goods.


Chloé Papazian is a Research Fellow at the Brexit Research and Policy Institute at the Dublin City University. She is finishing her Ph.D. at the Faculty of Law of the European University Institute, Florence, Italy. Her thesis focuses on WTO subsidy law and EU State aid law. She holds a LL.M in European legal studies from the College of Europe. Her research interests relate to WTO law and EU law, as well as international energy and environmental law.