The Volus.
They played a massive role in the war effort by managing the galactic economy and keeping it afloat, despite the conquest and widespread destruction of many colonies and home worlds. As such after the Turians, Humans, and Asari, they played one of the largest roles in the war effort. You can't find a war without a deep war chest, and had the galactic economy gone belly up the Council species would have been finished. The Volus also played a vital role in the construction of the Crucible and fielded significant support fleets to war's final campaign.
They would certainly get a seat before the Quarians or Krogan. While both of those species also potentially played large roles in the war effort (particularly the Krogan), they also both start as outsiders. They were allies, rather than members of the Citadel. The Volus on the other hand have been associate members of the Citadel for thousands of years.
The main factor I'd see as working against the Volus getting a seat is their subordinate status to the Turians. The Volus getting a seat potentially disrupts that relationship and may end the protectorate status, as they'd now have a leader who was the peer of the most politically powerful Turian. As such, the Turians might oppose it as well as some Volus who'd prefer to maintain the status quo.
That being said Sparatus (or his replacement) is only one Councilor, and if the Human, Asari, and Salarian Councilor's vote "Yes" for the Volus gaining a seat, it is a done deal.
Modifié par Han Shot First, 10 septembre 2013 - 04:18 .