Charter drafters will stand firm by their proposed draft on the state power structure that encompasses the premiership, election system, Senate and relationship between the executive and legislative branches.
Concerns have been raised by politicians and members of the National Reform Council (NRC) over those issues, especially the mixed-member proportional system (MMP) and the non-elected prime minister.
The MMP system is non-negotiable for any review because it's the important principle of this charter, said Borwornsak Uwanno, chairman of the Constitution Drafting Committee (CDC), who led his colleagues from the CDC in an interview with Nation Multimedia Group on Wednesday night.
"It's a fair system. It will pave the wayfor a coalition government to prevent 'one-man rule' in the country and ensure no 'winner takes all'," he said.
"We need reconciliation now, don't we? Otherwise the same political disputes will repeat themselves again when the election winner forms the government and the runner-up stages protests," he said.
The CDC adopted the German-style MMP system to make an election reflect the aspirations of all voters, as the number of seats allocated to political parties in Parliament is commensurate with the proportion of votes each party receives nationwide.
Small parties and independent candidates will also have a better chance at the polls.
Borwornsak said that in the initial phase, the system would be good for building reconciliation and preventing any party from getting too arrogant.
"We realise it [MMP] isn't perfect. Let's just try it for five to seven years. If it doesn't work, it can be reviewed," he said.
Suchit Bunbongkarn, another CDC member, said the system would lead to a coalition government. But a coalition government does not always mean a weak one. If they do it right, there will be unity in the government.
Independent MPs won't cause political parties to become weaker.
"If your political party weakens when you have independent MPs, you are to blame. It means you are weak and can't manage your party well enough," he said.
The NRC is scheduled to debate the final draft from April 20-26 before proposing recommendations to the CDC for review. The drafters have 60 days to consider the proposals before submitting the new charter to the NRC for approval.
According to the provisional charter of 2014, if the NRC votes to reject the new charter, both the NRC and CDC will be dissolved and the process of drafting a new charter will go back to square one and the whole process restarts.
"It can't be helped if they [NRC] disapprove the draft. Why don't they think they will also suffer if the draft is rejected? Many reform issues remain to be finished by them," Suchit said.
However, CDC spokesman Lertrat Ratanavanich believes the NRC would finally vote for the draft.
Only five to 20 members would reject the draft. The 41 political parties invited to discuss with the CDC also supported the MMP system, he added.
Another controversial issue in the draft is the non-elected PM. Borwornsak defended this principle, saying the drafters aimed at avoiding a coup or troubling the monarchy in the event of a political deadlock.
"You need to ask Abhisit [Vejjajiva, Democrat Party leader], Somchai [Wongsawat, former PM] and Bhokin [Bhalakula, Pheu Thai member] if they will vote for [an outsider to become the PM]," he said.
Although most CDC members support a national referendum for the charter, the chairman said the decision did not depend on them.
"When I met PM Prayut Chan-o-cha in the so called "five rivers" meetings, he kept asking me if it should be held and I said yes," he said.
He declined to say how the PM will decide but said Prayut was keeping his last card close to his chest and would decide when the right time comes.
The premier also asked him what to do if any political dispute arises after the next election is held.
"I still can't figure it out," the chairman said.
The final draft charter with all 130 pages and 315 articles will be handed out to the NRC next Friday.
Almost half of the draft consists of new clauses and ideas that were never included in previous versions, such as those on reform and reconciliation.
While politicians were concerned about the intensive measures to scrutinise them in the draft, the CDC placed its hope on its ability to help cleanse the old habits of politicians.
CDC member Charas Suwanmala said the charter would help reduce the cut-throat competition among politicians.
"We wrote the rules to allow them [to come to power] like before but they can't have the same behaviour," he said.
Asked if the charter is designed for a national government, Borwornsak said it's interesting.
"You may want to live with the election winner being the government and the runner-up taking to the streets for 10 more years. But if you want them to run the country together, you can."