The main opposition Move Forward Party (MFP) will renew its attempt to seek a referendum to rewrite the charter via a fresh motion to be raised in parliament on Wednesday.
The motion, to be sponsored by the MFP, including spokesman Parit Wacharasindhu, is the first item on the parliamentary debate agenda on Wednesday.
Many lawmakers are concerned the sweeping changes proposed by the MFP would lead to the amendment of the crucial chapters 1 and 2 of the constitution.
Chapter 1 contains sections defining Thailand as a single, indivisible kingdom with a democratic regime and the king as the head of state, while chapter 2 stipulates sections pertaining to royal prerogatives.
Adisorn Piengkes, a Pheu Thai Party MP for Si Sa Ket who serves as chief government whip, said on Sunday the motion was lodged in compliance with the referendum law. Government coalition MPs will meet to determine their positions on Tuesday, he said.
The government is open to listening to what the MFP has to say. If the motion clears the House of Representatives, it will be forwarded to the Senate before it reaches the cabinet for approval.
Mr Adisorn said the government, which is against amending chapters 1 and 2 of the constitution, is under no pressure to consider the motion.
The government has set up a committee to study the proposal, while two sub-panels will gauge public opinion and draw up referendum guidelines.
The main committee's chair, Phumtham Wechayachai, said earlier that while the sub-panels do not have a fixed deadline, both are expected to wrap up their assignments around the end of the year.
Mr Adisorn said the government's bid to press for a referendum is a quicker alternative to MFP's motion, which requires the time-consuming process of being approved by both Houses.
The motion is likely to hit a snag with the Senate, which opposes it. There is also the issue of the government and the MFP initiating parallel referendums, which may be construed as a duplication.
Mr Adisorn said even though the MFP reserves the right to submit its motion, it should consider its reason and the motion's suitability.
While it is vital to many voters that the amendment goes ahead, the process will likely be directed by the government.
"The government and the MFP are united in their quest for a charter amendment, although the means of pursuing this are different," the government chief whip said.
Mr Adisorn said the MFP should be reminded that trying to change the entire charter had cost the main opposition party its chance to form a government due to strong opposition to its uncompromising stance.
Mr Parit insisted the party is correct in proposing unrestricted changes to the charter.