Civil society groups and trade unions have presented compelling evidence that implementing a just transition, including commitments in the Paris Climate Agreement, is incompatible with the provisions of the Energy Charter Treaty (ECT). As negotiations to modernise the ECT began in December 2019, 278 organisations signed a letter calling for a radical rethink. They argue that the provisions of the ECT have repeatedly been used to undermine climate action, and that investor arbitration puts public budgets at huge risk, threatens all kinds of environmental protection and can be used to attack measures to make energy affordable and put it under public control. Moreover, it creates a risk for public authorities wanting to favour renewable energy.