About 60 members of the National Legislative Assembly and many ministers are resigning their positions to become senators.
NLA vice president Pirasak Porjit said on Tuesday that he was among the nominees for the senate that the National Council for Peace and Order would propose for royal approval on Friday. About 60 other NLA members would also resign to sit in the new senate.
They included NLA president Pornpetch Wichitcholchai, NLA vice president Surachai Liangboonlertchai, Somchai Sawaengkan, Tuang Antachai, Wanlop Tangkhananurak and Klanarong Chantik, he said.
Mr Pirasak said he believed the senators and lower house representatives could work together. Their first joint meeting was to vote for the next prime minister.
Deputy Prime Minister Wissanu Krea-ngam confirmed that many ministers would resign to take seats in the senate and that Tuesday's cabinet meeting would be their last.
Their resignations would have to take effect by Thursday. A majority of the ministers would remain in the cabinet, he said
Under the 2016 charter, the 250-strong regime-appointed senate will serve a five-year term. Its first task is a joint sitting with the new house of representatives to vote for a new prime minister.
Fifty are selected from a shortlist of 200 candidates chosen in an intra-group process by various social groups and professions. Another 194 senators are chosen directly by the NCPO, and the remaining six seats are reserved for the three armed forces leaders, the supreme commander, the defence permanent secretary and the national police chief.
The senators must be appointed within three days of the general election results being endorsed.