Coalition parties want the new constitution written by 200 people, 150 of whom are elected, within 240 days, according to their bill to be sent to the House speaker on Tuesday.
The bill will likely be deliberated by a joint sitting of the House and Senate during Sept 23-24, according to Patcharin Samsiripong, a spokeswoman of Palang Pracharath, the core party of the coalition.
Under the bill, the composition of the constitution drafting council is: 150 members elected by people, 20 picked by the House and Senate, 20 chosen by rectors and 10 screened by the Election Commission from among school and university students.
Political officials, MPs, senators and cabinet ministers and people who lack qualifications to be MPs may not apply.
The number of council members from each province is based on its population, but not fewer than one.
The Election Commission will hold a nationwide election within 90 days.
The council will have 240 days to write the new draft charter. Once done, a joint sitting of both houses (500 MPs and 250 senators) will decide whether to accept it by a majority vote (376), but cannot make changes to it.
If the draft is approved, it will be sent to the King. If not, it will be put to a referendum within 45-60 days and then sent to the King if people accept it.
If people reject it, the process may be restarted if approved by two thirds of both houses. Members of the previous constitution writing council may not rejoin the process.