The suggestion was raised in a joint meeting between the NLA and CDC yesterday.
NLA member Somchai Sawangkarn said the additional question could be interpreted in both a broad or narrow manner.
One interpretation would be that the Senate could nominate prime ministerial candidates then vote along with the MPs to select the PM, Somchai said after the twohour meeting.
Another was that the Senate could only vote in the later process to decide who would be premier, Somchai said.