The Lisbon treaty remedied this by amending Article 6(2) TEU to place an obligation on the EU to accede to the ECHR, and accession proceedings were opened. The mandatory accession procedure, set out in Article 218 TFEU, is cumbersome and complex. Nonetheless, in April 2013, a draft agreement on accession was agreed between the Council of Europe and the European Commission. Given that a number of member states – both from within and outside the EU – initially had reservations about the terms of EU participation in the Convention system, it is some achievement that agreement between them was reached, albeit in a regrettably secretive process on the EU side, as the action brought by Leonard Besselink for access to accession documents revealed.