As Daijo-daijin (Grand minister of state), which was above Sadaijin in rank, was not a permanent position, it was not appointed in the absence of a qualified person; therefore, in such a case, Sadaijin was the top rank in Daijokan.
左大臣の上には太政大臣が存在するが、常置の職ではなく、その資格がある人を欠く場合は置かれず、その場合には左大臣が太政官の最高位であった。