The panel to draft a referendum on amending the charter will meet on Tuesday after the cabinet this week approved the appointment of its 35 members, according to member Chusak Sirinil.
He said the panel, headed by Deputy Prime Minister and Commerce Minister Phumtham Wechayachai, will discuss changes to the committee after the Move Forward Party (MFP) decided not to participate.
Mr Chusak, who is a Pheu Thai-list MP, said the committee's main tasks are to reach a consensus on the number of referendums needed to determine the role and the composition of the proposed drafting assembly (CDA).
Regarding the referendum process, he said views are split as to how many rounds may be required, and the procedure must also comply with an earlier Constitutional Court ruling.
In 2021, the Constitutional Court ruled the public must approve any move to amend the entire charter, and if a rewrite is approved, another referendum must be held to approve the content.
Based on the ruling, at least two rounds are required, he said but noted that some argue that a third round may be needed.
On the role and the make-up of the CDA, Mr Chusak said some feel that the CDA should be directly elected while others argue it should also comprise appointed members.
The debate on these two issues must be finalised first, he said, adding he was confident that the matter will be settled by the end of the year.
Meanwhile, MFP leader Chaithawat Tulathon said on Friday the party would still make suggestions to the committee but had formally decided to opt out.
He urged the government to listen to all stakeholders and give them space to voice their opinions to avoid a new round of political conflict.
MFP chief adviser Pita Limjaroenrat reiterated the party's stance that it wanted wholesale change and that the charter drafting assembly should be directly elected.
He said the MFP had not joined the panel as the party feared it had been formed to stall the charter rewrite.