Consequences of the EU's withdrawal from the Energy Charter Treaty

The European Commission recommends the withdrawal of the EU from the Energy Charter Treaty (ECT). The question arises: What will happen to the EU member states that remain in the Energy Charter Treaty? We commissioned a study on this.
The study examines the responsibilities of EU member states under the Energy Charter Treaty should the EU, but not the member state, withdraw from the ECT. It concludes that EU member states are highly likely to be held accountable for the implementation of binding EU requirements under the ECT.