Defron

High Minister Defron was a Zerugian who organised the negotiations and brought both sides together. When first meeting The Doctor and Martha, he believed they were GA observers. He explained to them that Castle Extremis was the head of the Sarandon Passage. Anthium was on one side and Zerugma on the other. When Secretary Chekz was killed, he was astonished to have a murder during the conferences.

As apparent GA observers, Defron had The Doctor and Martha be present at the further conferences and the final handing over of Castle Extremis to the GA in case of any problems or awkward questions. At the actual conference when General Orlo took over, he was surprised to learn that they weren't actual part of the GA council. (NSA, Martha In The Mirror)