In January 2019, EU Member States issued three declarations concerning
the ‘consequences of Achmea’ which stated that all claims under
intra-EU BITs were contrary to the EU legal order, and that tribunals presiding
over such claims have no jurisdiction as there is no valid consent to
arbitrate. The declaration signed by a majority of EU Member States (‘Majority
Declaration’) extended this proposition to intra-EU claims under the Energy
Charter Treaty. Following this, a number of EU Member States have sought to
argue that the Majority Declaration is a subsequent agreement between the
States Parties to intra-EU investment treaties – or evidence of a subsequent
practice establishing their agreement – that the dispute resolution provisions
in those treaties must be interpreted to exclude intra-EU disputes from their
scope and thus from the jurisdiction of tribunals constituted thereunder,
relying on Article 31(3)(a) and (b) of the Vienna Convention on the Law of
Treaties (‘VCLT’). This paper considers: (i) the key cases in which the
Majority Declaration has been invoked to contest jurisdiction in, or seek the
termination of, intra-EU arbitration proceedings; (ii) the application of
Article 31(3)(a) and (b) of the VCLT; and (iii) other fundamental tenets and
rules of international law discussed in relation to those cases.