The Planetary Council consists of the leaders of all of the human factions.
Once one faction has obtained commlink frequencies for all of the other human factions, they can convene the Planetary Council at which point all human factions will gain commlinks for each other.
Members can vote on various Council Proposals with each member having one vote and the Planetary Governor (if there is one) exercising a veto. In elections for Planetary Governor (and Supreme Leader), each faction casts votes equal to the total size of all of its bases. This total may be modified by faction powers and by possession of The Empath Guild and Clinical Immortality secret projects.