23. We asked our witnesses to gauge the influence which each of the EU institutions would exercise over the negotiations. Both thought that the Member States would exercise the greatest influence, despite the conduct of the negotiations being the responsibility of the Commission. Sir David said: “I would envisage that, formally speaking, the Commission will do the negotiations, but in the way things work I strongly suspect that the Council’s internal services will also be closely involved right the way through, as well as the other Member States.”28 Professor Wyatt said that the Member States “would be in the driving seat” and would “call the important shots”. He provided a helpful insight into how the Member States would exercise their inf luence through the Council:
“The European Council is not going to be hands-on all the time. Who will be hands-on all the time will be the Committee of National Representatives, which is overlooking the Commission negotiations. The normal committee is the Trade Policy Committee, which I think meets once a month, but its deputies meet every week … Changing of the negotiation mandate is possible and could, and would, happen.”29
24. Both witnesses agreed that the European Parliament’s power to refuse to give consent to the draft withdrawal agreement also gave it considerable influence.
Read it all if interested [pdf] h/t Bp G Kings twitter