Consolidating the EU in the area around the Strait: Gibraltar

Rock of Gibraltar. Photo: Pavol Svantner @palsoft

Original version in Spanish: Consolidar a la UE en el área del Estrecho (2): Gibraltar.


This analysis examines the presence of the EU as an actor in the territorial issues and disputes in the area around the Strait of Gibraltar, as well as Spain’s strategic options, placing the spotlight on Gibraltar.


The Ceuta immigration crisis of May 2021 and the claims laid to the Western Sahara and the cities of Ceuta and Melilla by Morocco highlight the complexity of the area around the Strait of Gibraltar for Spanish foreign policy. This comes in addition to the dispute surrounding Gibraltar which, in the wake of Brexit, seeks an accommodation with the EU for a new status and relationship with Spain. The present analysis posits the possibility of Spain pursuing the involvement of the EU in the territorial issues in the area and region of the Strait as a medium- and long-term strategy, conceiving these as EU spaces in which Spain has jurisdiction, competences and special responsibility as a member state.


Spain faces a range of frontier disputes and territorial claims in the area around the Strait of Gibraltar (Gibraltar, Ceuta and Melilla). In the case of Gibraltar, the incorporation of the EU into the tangible and institutional structures of cross-border cooperation has opened up new avenues of understanding and stability in the relationship with Spain. There is even the prospect of inclusion within the Schengen area and a FRONTEX deployment in Gibraltar ahead of the forthcoming and decisive treaty on the future EU-UK relationship on Gibraltar.

Spanish foreign policy in the Strait of Gibraltar area

The Strait area being referred to here is an extensive zone encompassing both ends of the Strait of Gibraltar, where a significant number of sovereignty and border issues cluster together with territorial claims and numerous uncertainties about maritime frontiers, in a part of the world that is vital to Spain (Ceuta, Melilla, Gibraltar, the Rota military base, maritime traffic, the ports of Algeciras and Tanger-Med, etc). The Strait region is larger however, because it can be understood to include the neighbouring and adjacent states to the south of Spain’s land and maritime territory, resulting in a larger zone (Morocco, Algeria, the Western Sahara and, in some contexts, Mauritania).

Since the return of democracy, Spanish foreign policy has been highly active in terms of staking a claim to Gibraltar. There are two different but linked and intertwined aspects that coexist here: cross-border cooperation (years of profound cooperation were witnessed with the tripartite Forum of Dialogue, running from 2004 to 2011); and the issues of sovereignty, taken up with the UK since 1984, which have generated occasionally significant negotiations (co-sovereignty in the Aznar-Blair period, from 2001 to 2002), but also abrupt periods of confrontation that affected Spanish-British relations (the sinking of concrete blocks in the water around the isthmus and an acute crisis when José Manuel García-Margallo served as Foreign Minister).

Spain has never drawn a connection between the Gibraltar and Moroccan claims. The fact is that Spain considers them quite different legal situations in objective terms. In the international media and courts of opinion, however, a degree of association or similarity is drawn between the situations of Gibraltar on the one hand and Ceuta and Melilla on the other, settlements on opposite sides of the Strait.

The EU as an actor in the Strait

The EU has traditionally maintained a presence in the area of the Strait, albeit in a secondary role. This is more evident with territorial issues, where the EU has tended to play a supporting and facilitating role in the agreements between states.

Gibraltar once formed part of the European Community and the EU under the auspices of the UK, and partially applied EU law (1973-2020).In this period the EU was a highly important actor in Spanish-UK relations with regard to Gibraltar. It even played the role of an interested mediator, intervening as the oversight body befitting international organisations in bilateral disputes (for example the Fact Finding Missions during the period of lengthy queues at the Spain-Gibraltar border),1 in a blend of mediation and acting as guarantor of EU law prevailing in Spain, the UK and Gibraltar. In hindsight, the fact that the UK and Spain belonged to the EU had considerable influence on aspects of the bilateral dispute relating to cross-border cooperation and issues of sovereignty.And, indeed, the EU’s mediating and facilitating role in removing the rough edges from the bilateral confrontation had considerable impact on the practical aspects of EU law that have been applied to Gibraltar and the Campo de Gibraltar district.

The point to be emphasised here is that for some time there has been a notably enhanced role played by the EU in territorial issues and disputes in the Strait area. In the specific case of Gibraltar, this involved making a decisive contribution as the mediating international organisation to the regulation and legal status of Gibraltar in its relations with the EU and Spain, following Brexit and the UK’s departure, which came into effect on 1 February 2020.

The EU in the Gibraltar dispute following Brexit

Brexit, the British withdrawal from the EU, consists of a series of treaties and agreements to facilitate an orderly departure. Negotiations began in 2017 and have still not been concluded with regard to future EU-UK relations. These historic circumstances have led to a need to provide Gibraltar with a new European status, something that must receive Spain’s approval, given that, in accordance with what is known as Clause 24, any agreement regarding Gibraltar requires prior agreement between Spain and the UK.

The process of the UK’s withdrawal has been set out in various treaties, reflecting this prior Spain-UK agreement and the specific provisional and future status of Gibraltar with regard to EU law: the Brexit Withdrawal Agreement (in force), the treaty on the future relationship between the EU and the UK (not yet in force) and a specific EU-UK treaty on Gibraltar (pending negotiation).

The Spanish position has been to frame Gibraltar’s new status within an ‘area of shared prosperity’ with the Campo de Gibraltar district and Andalusia, and to greatly strengthen cross-border cooperation. Until now the most important aspect has been the Withdrawal Agreement, which focused on the way the Gibraltar issue was dealt with in cross-border cooperation with Gibraltar. The circumstances surrounding Brexit have highlighted the existing problems with the Campo de Gibraltar and the need to take this district’s interests into account; especially the rights of cross-border workers, defence of which unites all political parties in Spain. For years there has also been an urgent need to regulate the problems of daily life and the most pressing aspects of the dispute, devising a modus vivendi with Spain, given that both the district and the municipality nearest to Gibraltar, La Línea, bear the daily brunt of the historical dispute.

Gibraltar in the UK’s withdrawal treaties

The first treaty, the Agreement on the Withdrawal of the UK from the EU,2 in force since 2020, regulates Gibraltar’s current situation. It contains the Gibraltar Protocol, which incorporates four Memorandums of Understanding (Spain-UK MOUs, signed in 2018), essentially regarding cross-border cooperation: citizens and cross-border workers, tobacco, the environment, and customs and police cooperation. The protocol also takes into account the issues later regulated by the international treaty on taxation and the protection of financial interests, bilaterally negotiated by Spain and the UK in 2019, and which came into force in March 2021 (Spanish State Gazette nr 62, 13/III/2021).

The Gibraltar Protocol and the four memorandums signed in 2018 created an institutional system or format for cross-border cooperation with the most pressing issues to be resolved, so that it may be said that the necessary modus vivendi with Gibraltar is made up of EU law with this withdrawal agreement (plus the MOUs).3

Moreover, the following ideas from the withdrawal agreement concerning Gibraltar and the role of the EU merit special emphasis:

  1. Cross-border cooperation is regulated by primary law, because the protocol is an integral part of the withdrawal agreement. The foregoing has the immense significance of safeguarding essential areas of cooperation with Gibraltar by means of an international treaty, thereby lending the EU’s backing and legal protection to the previous Spain-UK agreements. This is a legal protection bestowed upon cross-border cooperation and has been achieved thanks to the EU.
  2. Although they are different legal instruments (an UK-EU Treaty Protocol on the one hand and the Spain-UK MOUs on the other), the combination comprises a consistent legal framework with institutional and subject-matter links. Moreover, a monitoring structure for these agreements has been created (working groups and committees, a specialised Gibraltar Protocol committee and a mixed UK-EU withdrawal agreement committee).
  3. This original institutional system for dealing with Gibraltar issues, with the participation of the EU, will involve the ‘mediation’ of this international organisation in the dispute, institutionally and materially.
  4. The combination of the treaty (EU primary law) and Spanish-British ‘soft’ law (the Memorandums of Understanding) makes a good fit with the parties’ interests and reality. Spain’s accords with the UK on Gibraltar have always made use of ‘gentlemen’s agreements’ or ‘soft’ law (non-normative agreements such as communiqués, declarations and memoranda, which are difficult to classify in terms of their international and domestic legal impact); but this recognition by the EU is a novel aspect deriving from the withdrawal agreement, by providing the new cooperation format for Gibraltar.

A second treaty, the EU-UK Trade and Cooperation Agreement,4 dated 30 December 2020, is not yet in force and will not apply to Gibraltar.

A third treaty will be the specific UK-EU treaty for Gibraltar. Although negotiations have not yet officially started, an in-principle agreement was adopted on 31 December 2020.

The ‘In-principle agreement’ of 31 December 2020, agreed on Gibraltar and on Brexit between Spain and the UK,5 is an instrument that sets out to establish the essential content of this future EU-UK treaty on Gibraltar. It is an ‘understanding regarding fundamental elements’ for the future relationship between the EU and Gibraltar and serves as a way of drawing up negotiating guidelines for this specific treaty that has yet to be drafted.

The essence of the ‘In-principle agreement’, as an informal document conveyed to the EU authorities in Brussels, comprises important agreements for the short, medium and long-term future. It is a Working Paper with letters from Spain and the UK’s Permanent Representatives to the EU, dated 31 December 2020, addressed to the secretaries general of the EU Commission and Council, attaching a ‘non-paper’, with 25 stipulations and three annexes.

Notable among the contents of the ‘In-principle agreement’ (transport, the environment, a level playing field, data and a financial mechanism of cohesion) is everything related to mobility and cross-border transit, with the majority of articles and annexes devoted to the circulation of citizens and cross-border workers. The inclusion of Gibraltar in the Schengen area is striking –something that has been interpreted as entailing the demolition or dismantling of Gibraltar’s border fence (‘removing physical barriers’)– and the setting up of Schengen area entry points at the port and airport. This involves a joint deployment by FRONTEX at these points over the next four years and Spanish involvement as the Schengen state responsible, in a measure where some details are yet to be finalised.

This ‘In-principle agreement’ will be taken into account by the Council and the Commission for the negotiating mandate of the specific treaty on the future UK-EU relationship on Gibraltar, a negotiating mandate that has still not been adopted. The essential content will furnish the future UK-EU treaty on Gibraltar, which will need to enshrine them in its articles before going through the necessary parliamentary scrutiny and examination for ratification prior to coming into force.

There is a delay in terms of the initial forecasts which envisaged that the UK-EU treaty on Gibraltar would have already been approved and in force by July 2021. The issues are of course highly complex and moreover the ‘In-principle agreement’ requires the complementary conclusion of other Spain-UK agreements to enable Brussels to assess its technical viability and formally adopt the negotiating mandate, something that would get the negotiating phase of the UK-EU treaty on Gibraltar under way. When it is concluded and comes into force, the UK-EU treaty on Gibraltar will provide a firm and stable international and European legal framework, with notable integration of Gibraltar into common European territory in collaboration with Spain.

In the context of the withdrawal agreement and subsequently the future relationship, Spain seems to have thus adopted a pragmatic position for the normalisation of cross-border cooperation as a means of creating ‘an area of shared prosperity’. This position requires that the EU be admitted decisively and explicitly, with clear acknowledgement of its role, into the institutional and material spheres relating to cooperation with the UK and Gibraltar.

In short, the EU has become, with the circumstance of Brexit and the change in Gibraltar’s international and European status, the essential actor in implementing cross-border cooperation between Spain and Gibraltar.

A distinct issue for the future is the question of sovereignty and whether the EU should intervene as a necessary element in the search for imaginative solutions to resolve the historical dispute.6 In any event, in this avenue of cooperation that has opened up with the UK agreement under the normative umbrella of the EU, Spain opens possible windows to a negotiated settlement that seeks ‘a 21st-century version of sovereignty’.7

Trickier issues remain in bilateral Spain-UK relations, in particular the elephant in the room that Spain has never addressed: the very serious risks that British military bases (naval, aerial and intelligence bases) pose to the Bay of Algeciras and its 300,000 inhabitants. These include the RAF’s military airport, with the proximity of its runway to the residential districts of La Línea, and the RAF munitions, arms stores, fuel and explosives held at the airport. There is also the naval base, where nuclear-propelled submarines are moored and repaired,8 and even submarines carrying intercontinental nuclear missiles.9 There has been no agreement whatsoever with Spain about what to do in the event of an accident, nor have any civil emergency or evacuation plans been coordinated with Spain. Nor is there any democratic scrutiny by the Spanish parliament (in contrast to the agreements struck with the US on the Rota and Morón military bases) regarding these British bases and their dangers.

Spain’s strategic options

In light of Spain’s trajectory and experiences in the territories and borders in the Strait area, it may, in general terms, adopt the following strategies on Gibraltar: (1) the traditional strategy of keeping its claim to the Rock alive, with a stance involving greater and lesser degrees of confrontation with the UK; (2) the strategy of taking the initiative, adopting an alternative sovereignty policy on Gibraltar and offering possible solutions to underlying issues (in line with co-sovereignty or the internationalisation of the territory); and (3) the option favoured by the present author of decisively involving international organisations, specifically the EU, in territorial claims.

This latter strategy would represent a shift in the traditional position and policies while also strengthening Spain without directly impinging on the core bilateral conflicts regarding sovereignty or the underlying claims. The EU’s involvement in Gibraltar may pave the way to new scenarios in cross-border cooperation, such as those that have already opened up with the idea of the ‘area of shared prosperity’. In the future it might be possible to propose symbolic sovereignty alternatives or the joint exercise of sovereign powers and competences, with the EU’s involvement.


The territorial issues in the area of the Strait have an extraordinarily destabilising potential for the countries concerned, vulnerable as they are to unforeseen developments. There are both active (Gibraltar) and passive claims (Morocco’s with Spain); these are ongoing and may sooner or later emerge in a host of issues, in a region that is strategic for Spanish and Euro-Mediterranean security.

As a means of strengthening Spanish strategy in the Strait area, it is proposed that Spain should pursue a strategy of internationalisation by way of the international organisations with the most direct competence, principally the EU, which should consolidate their involvement in these territorial issues. This would also help to forestall and lend a European framework to the problems, helping to blunt the thorniest aspects of relations with the UK and Morocco.

This strategy is reaping dividends with the UK. Spain has secured the EU’s in-depth involvement in aspects of the dispute relating to cross-border cooperation. The outcome has been a provision in the Gibraltar protocol of the withdrawal agreement of January 2020 covering cooperation aspects, also regulated by the MOUs, and a Spanish-British and also EU institutional structure. This manifests itself in a novel ‘hard’ law/EU treaty and ‘soft’ law/Spanish-British memoranda combination.

It would be reasonable for this original modus vivendi, constructed courtesy of the EU, and revolving around the international organisation as a mediator, to be extended to the treaty on future EU-UK relations regarding Gibraltar. For the purposes of this treaty an in-principle agreement of 31 December 2021 has been drawn up, which seeks a greater degree of interweaving between Gibraltar and the EU and Spain, integrating Gibraltar into the Schengen area.

In short, it is a matter of consolidating the reality that the Strait is a space of the EU, drawing out all the consequences of the fact that Spain, as a member state in the border area, is the guarantor of the EU in the area and region of the Strait, with its law and democratic and human rights-focused principles and values. This is thus the case made to the EU and the UN as structures integrated into the Spanish position, for the purposes of prevention, strengthening the bilateral dynamics with the UK and Morocco, and finding a solution to intractable obstacles to cross-border cooperation and sovereignty issues.

Alejandro del Valle Gálvez
Professor of Public International Law and director, Jean Monnet ‘Migration and Human Rights in Europe’s External Borders’ Centre of Excellence, University of Cádiz | @Adelvalle_Cadiz

1 Alejandro del Valle Gálvez (2014), ‘Gibraltar, controles en la verja y nuevo diálogo ad hoc: la UE se involucra en la controversia’, ARI, nr 62/2014, Elcano Royal Institute, 19/XII/2014.

2 Agreement on the withdrawal of the UK of Great Britain and Northern Ireland from the EU and the European Atomic Energy Community, adopted in October 2019, OJ L 29, 30/I/2020.

3 The Spanish and English-language versions of the withdrawal agreement, protocol, fiscal treaty and MOUs are included in the Cuadernos de Gibraltar/Gibraltar Reports, nr 4, 2021, Documentation II,

4 Trade and cooperation agreement between the EU and the European Atomic Energy Community, of the one part, and the UK of Great Britain and Northern Ireland, of the other part, 30/XII/2020, OJ L 444, 31/XII/2020.

5 The text is available at Cuadernos de Gibraltar/Gibraltar Reports, nr 4, 2021, Documentation VI,

6 See, for example, ‘Gibraltar, ciudad de las dos coronas’, Ignacio Molina & Alejandro del Valle (2018), El País, 28/III/2018.

7 In the words of the Spanish Foreign Affairs Minister in an interview in El País, 9/II/2020.

8 Luis Romero Bartumeus (2021),‘Las escalas de submarinos nucleares en Gibraltar y Rota, y los Planes de Emergencia Radiológica’, Cuadernos de Gibraltar – Gibraltar Reports, nº 4.

9 ‘Llega a Gibraltar otro submarino nuclear – El USS Alaska lleva misiles balísticos intercontinentales’, Noticias Gibraltar, 28/VI/2021.