The Election Commission has proposed that the 21 constitution writers who sit on the National Reform Council (NRC) should not be allowed to persuade people to accept the charter draft in the referendum.
EC chairman Supachai Somcharoen said on Saturday that the commission had finished drafting the announcement of a referendum, to be submitted to the National Legislative Assembly (NLA) for endorsement.
The referendum will be held only after the NRC votes to endorse the charter. The NRC is scheduled to vote on Sept 6.
It has been speculated that the charter draft would be endorsed. It remains unclear whether the 21 members of the Constitution Drafting Committee (CDC) will be allowed to vote on their own draft. The CDC has 36 members in total and 21 of them hold seats on the 247-member NRC.
Critics have said it would be a conflict of interest to allow the drafters to vote.
Deputy Prime Minister Wissanu Krea-ngam said earlier that there was no law or rule that prevents the charter writers from voting on the document they had written.
NRC chairman Thienchay Kiranandana agreed, but said that since the vote would be done openly, the CDC members could be allowed to join and their votes would be deducted later if problems emerged.
Some NRC members believe it would be unethical for the CDC members to vote. They point out that former MPs and senators in the Yingluck Shinawatra government were almost impeached for the same behaviour.
They had been accused of having a conflict of interest when they voted on a charter amendment that would enable them to run in the next Senate election.
Reports of a rift in the NRC have also started to circulate on a Line chat group. NRC member Niran Pantharakit openly disagreed with the idea of allowing the charter writers to vote, prompting responses from CDC chairman Borwornsak Uwanno.
Mr Niran claimed that apart from seeing the charter they wrote put into effect, the CDC had other reasons to want the document passed. He said the CDC members could continue to sit on the reform body and write organic laws related to the charter if it passes. They would be paid 6,000 to 9,000 baht for each meeting.
There are 247 NRC members and at least 124 votes are needed to pass the charter draft if the CDC votes are included.
Excluding the CDC votes, the vote will likely lean toward a "no". Many provincial NRC members have made clear that they will reject it because it would be hard to explain "undemocratic" elements of the draft to average citizens. Members of the NRC panels on politics and laws also made clear they would reject it. Together, they amount to 100 votes.
The EC also proposed on Saturday to hold a forum in which both supporters and critics of the charter draft could air their views independently and fairly.
Mr Wissanu said this week that anti-charter campaigns by any group through Line or other chat applications, video clips, forums or text messages would be illegal.
He said the move was tantamount to instigating unrest and violated the junta's orders against sedition.
The comment was heavily criticised for its stance. Samart Kaewmeechai, a former Chiang Rai MP of the Pheu Thai Party, said politicians were ready to explain to the people the flaws of the draft so they have information for their own judgement in the referendum.
Mr Wissanu did not say whether talking about the good points of the charter or promoting it would be banned as well.
