Parliament will vote on whether to accept in principle each of the six constitution amendment motions on Thursday, Parliament President Chuan Leekpai said on Tuesday.
The coalition, opposition and senate whips met on Tuesday, he said.
It was agreed that each side would get seven hours and 20 minutes in total for the debate, which would run from Wednesday to no later than midnight Thursday, when a voice vote would be taken on each motion.
For a motion to pass, a majority of the 750 members of both houses is needed. That majority must include one-third of the 250 senators (84) and 20% of opposition MPs.
After the vote, a 45-member extraordinary committee will be set up. The composition is senators (15), Palang Prachararth Party (8), Pheu Thai (8), Bhumjaithai (4), Move Forward (3), Democrat Party (3), Chartthai Pattana (1), Prachachat (1), Seri Ruam Thai (1), New Economics (1). They may include outsiders based on the quota.
On another motion to be submitted on Tuesday by Internet Law Reform Dialogue (iLaw), Mr Chuan said officials would speed up checking the 50,000 names of people supporting the bill. In any case, it would not put on the meeting agenda.
Suthin Klangsaeng, chairman of the opposition whips, said the debate would start at 9.30am on the two days. Wednesday's session would end at 1.30am, and Thursday's at 6pm.
Virat Rattanaset, chairman of the coalition whips, said the six bills would be debated at the same time.
All three sides have yet to discuss their stances on each bill.
The six bills are from Pheu Thai (1), coalition parties (1) and opposition parties (4).
The Pheu Thai version sets up a fully elected constitution drafting council, does not allow senators to vote on a prime minister and uses two election ballots, one each for a party and an MP.
The coalition bill also envisions a constitution drafting council, but with 150 members directly elected by people and 50 chosen among certain groups.
The four bills by the opposition parties remove the power of senators in voting on a prime minister, allow MPs to join them in voting on bills related to national reform; drop the endorsement of all laws, orders and announcements issued by the National Council for Peace and Order and use two election ballots.
