How is the Thai PM chosen in the next (March 2019) election? What is the procedure laid out in the Constitution?
Wikipedia provides some information, however, it's not entirely clear to me how that applies to the next election. I will lay out three quotes from Wikipedia and then explain why these seem conflicting.
Quote 1 from the appointment section of Wikipedia's page on the Thai PM:
The Prime Minister of the Kingdom of Thailand must be a member of the House of Representatives.
Quote 2 from the appointment section of Wikipedia's page on the Thai PM:
The nominee and eventual prime minister is always the leader of the largest political party in the lower house or the leader of the majority coalition formed after an election.
Under the current junta, the nominee for the office is selected by National Legislative Assembly, with the House of Representatives being abolished.
Quote 3 from Wikipedia's page on the 2019 Thai election:
Under the new constitution, all 250 members of the Senate, Thailand's upper house, will be appointed by the NCPO and be able to select the next prime minister.
Quote 4 from Wikipedia's page on the 2017 Constitution:
The bicameral Parliament could also select a candidate as Prime Minister who is not one of its members or even a politician. That person could become Prime Minister if the appointed Senate approves.
These quotes seem to conflict quite a bit. Quote 4 suggests the PM could be an outsider, whereas quotes 1 & 2 indicate the PM is a member of the lower house and already has a senior political position, respectively. Quote 3 says the PM is selected by the Senate, but given quote 2 that would be a choice between at most two people (leader of the largest party or the leader of a majority coalition).