The decision will increase public access to documents and hearings and include civil society in investor-state disputes under investment treaties. 

The Council of the European Union adopted a decision on the conclusion of the United Nations “Mauritius” Convention on transparency for Investor-State Dispute Settlement” (ISDS) on 22 May 2025.

This decision will bring greater public access to documents and hearings, as well as the inclusion of civil society in disputes brought by investors against States under investment treaties.

The Convention provides for the application of the United Nations Commission of International Trade Law (UNCITRAL) transparency rules to investment treaties signed before 1 April 2014.

These rules require public access to all documents, including tribunal decisions and party submissions, mandate open hearings, and allow third parties, such as civil society organisations, to submit contributions to the tribunal.

For treaties signed on or after 1 April 2014, the transparency rules automatically apply to disputes under the UNCITRAL arbitration rules, unless agreed otherwise by the parties. All EU agreements concluded after this date already incorporate enhanced transparency provisions.

The Convention applies to the Energy Charter Treaty being the only EU-level treaty included.

The decision taken on 22 May is an important step in the EU’s broader reform of investment dispute resolution, within the framework of the United Nations Commission on International Trade Law.

To date, 25 jurisdictions have signed the Convention, with nine of them (including Australia, Benin, Bolivia, Cameroon, Canada, The Gambia, Iraq, Mauritius, and Switzerland) having put it into effect.

The EU signature of the Convention took place on 2 July 2024.

On 18 December 2024, the European Parliament gave its consent to the conclusion of the Convention.