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On 29 June 2017 the Arbitral Tribunal rendered its Final Award  in the arbitration concerning a territorial and maritime dispute between the Republic of Croatia and the Republic of Slovenia.

This ruling is final and binding on both countries (Article 7 of the Arbitration Agreement).

Slovenia respects the final award  and expects the same from Croatia.



Cartographic representation of the state border between Slovenia and Croatia according to the award of the arbitral tribunal:

-  Cartographic representation (1) (4.8 MB)

 Cartographic representation (2) (4.7 MB)

 Cartographic representation (3) (4.8 MB)

 Cartographic representation (4) (4.9 MB)

 Cartographic representation (5) (4.6 MB)

 Cartographic representation (6) (1.4 MB)

- Cartographic representation (7) - maritime border 



Since Croatia rejected the arbitration ruling and its implementation, specific infringements of the European law have occurred. By not respecting the arbitration ruling and thus the rule of law, Croatia is also violating the fundamental principles of the European Union. Slovenia initiated proceedings against Croatia under Article 259 of the Treaty on the Functioning of the European Union (TFEU).


On 16 March 2018 Slovenia submitted a letter under Article 259 of the TFEU to the European Commission, informing it about the violations of the EU law by the Republic of Croatia and calling for action. 


Croatia was summoned by the European Commission to produce a written position on the specific infringements of the European law stated by Slovenia in its letter to the European Commission by 17 April 2018.


On 2 May 2018 the European Commission called an oral hearing , where both Slovenia and Croatia orally presented and further explained their positions.


On 18 June 2018 the three-month period during which the European Commission could deliver a reasoned opinion under Article 259 of the TFEU expired. The European Commission did not submit a reasoned opinion by that date.


On 13 July 2018 Slovenia filed suit against the Republic of Croatia owing to non-fulfilment of obligations pursuant to Article 259 of the Treaty on the Functioning of the EU.




Following a series of unsuccessful attempts to resolve the dispute over their land and maritime boundary, Slovenia and Croatia, with the facilitation of the European Commission, signed on 4 November 2009 an  arbitration agreement (1.7 MB) establishing an arbitral tribunal tasked to determine:

  • the course of the maritime and land boundary between the Republic of Slovenia and the Republic of Croatia;
  • Slovenia's junction to the High Sea;
  • the regime for the use of the relevant maritime areas.


According to Article 4 of the Agreement, in its deliberations concerning the junction and the regime, the Arbitral Tribunal must apply the rules and principles of international law, as well as equity and the principle of good neighbourly relations in order to achieve a fair and just result. Furthermore, it must take into account all the relevant circumstances.



The search for the solution to Slovenia and Croatia's border dispute can be broken down into five phases:

Arbitration Procedure

10 July 2015: the Arbitral Tribunal informs Slovenia and Croatia that the award can be expected in mid-December 2015. 


22 July 2015: the Serbian and Croatian newspapers Kurir and Večernji list report about alleged phone conversations between the Slovenian agent, Simona Drenik, and arbitrator Jernej Sekolec, and proceeds by publishing audio recordings of the alleged conversations. The following day, the Slovenian agent Drenik and the arbitrator Sekolec resign; Slovenia does everything in its power to preserve the credibility of, and trust in, the Arbitral Tribunal.


Nevertheless, Croatia notifies Slovenia on 30 July and the Arbitral Tribunal on 31 July of its intention to terminate the Arbitration Agreement. The arbitrator, appointed by Croatia, dr. Budislav Vukas, also resigns. Slovenia rejects Croatia's intention to unilaterally terminate this international agreement and notifies the Arbitral Tribunal respectively.


25 September 2015: the President of the Arbitral Tribunal appoints new arbitrators. 


2 December 2015: the Permanent Court of Arbitration announces that the Arbitral Tribunal will decide on questions arising from the letters sent by Slovenia and Croatia in July and August 2015 and invites the parties to make further submissions: Croatia by 15 January 2016 and Slovenia by 26 February 2016. In addition, it schedules a hearing in March 2016.  


26 February 2016: Slovenia files its written submission; in accordance with Article 6, paragraph 5, of the Arbitration Agreement, the content is confidential. 

17 March 2016: Slovenia presents its positions at a hearing held at the Permanent Court of Arbitration. The following day, the Court publishes a summary of the positions of both parties , noting that Croatia has not filed any written submission by 15 January 2016 or attended the hearing on 17 March 2016. 


30 June 2016 The Arbitration Tribunal announces "Arbitration between Croatia and Slovenia to continue ". The Tribunal's partial award  is available at the Permanent Court of Arbitration website.

19 June 2017: The arbitration tribunal has announced it will render its final award on the course of sea and land border between Slovenia and Croatia on 29 June .


Detailed timeline of events since 22 July 2015.



Slovenia has always fully supported the Arbitral Tribunal and the arbitration proceedings, which resulted in a legally-binding award on the border between the two countries in accordance with the Arbitration Agreement.



Who were the arbitrators

The Arbitral Tribunal consisted of five arbitrators: three of them (Gilbert Guillaume, Vaughan Lowe, Bruno Simma) were appointed by the two countries from a list prepared by the European Commission, and each country appointed one arbitrator of their own: Slovenia appointed Jernej Sekolec (replaced by Ronny Abraham 28 July 2015, who resigned on 3 August 2015), while Croatia appointed Budislav Vukas (resigned 30 July 2015). 


The Arbitral Tribunal appointed new arbitrators on 25 September 2015 Rolf Fife (N) and Nicolas Michel (CH) as national arbitrators. 


The Arbitral Tribunal was chaired by Gilbert Guillaume.



Arbitrators are to remain independent and impartial when carrying out their duties. The national arbitrator is to ensure that all main arguments put forth by the party which appointed them are appropriately deliberated; and is to remain independent and impartial when carrying out their duties.

An award shall always be made by a majority vote of the arbitrators. In the arbitration between Slovenia and Croatia no separate opinions were allowed.

Slovenia's representatives at the Permamnent Court of Arbitration

Slovenia was represented before the Permanent Court of Arbitration by:


  • Agent: Mirjam Škrk (Simona Drenik resigned as Agent on 23 July 2015)
  • Co-agent: Nataša Šebenik
  • Counsel and Advocates: Alain Pellet, Sir Michael Wood (20 Essex Street), Rodman R. Bundy (Eversheds LLP), Daniel Müller and
  • their assistants (Alina Miron, Eran Sthoeger, Natasha Harrington (Eversheds LLP) and Maja Menard).


The team representing Slovenia before the PCA also consisted of:

  • cartographers and hydrographers: Robin Claverly, Igor Karničnik, Martin Pratt, Primož Kete,
  • members of the project section for advocacy before the Arbitral Tribunal at the Ministry of Foreign Affairs,
  • Héloïse Bajer-Pellet, office for legal-technical support during the oral hearing.



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