Government MPs joined hands with senators to defer the charter rewrite vote by another month amid criticism that the process is a political game to shoot down all constitution amendment bills, including the one proposed by civil society group iLaw.
The move came despite strong opposition from the Democrat Party, which is a partner in the government coalition.
The opposition said postponing the vote on the six charter amendment bills yesterday was made under the order of "a powerful figure".
MPs and senators yesterday approved a proposal to set up a study committee, 432 to 255, with 28 abstentions. The vote on whether to accept the six bills is postponed by one month.
The MPs set up the committee with members and senators from government coalition parties, while opposition politicians refused to join.
Student activists and demonstrators who gathered outside parliament to monitor the vote expressed dissatisfaction with the resolution, pledging to step up their protests.
The proposal to set up the committee was put forward by Paiboon Nititawan, a Palang Pracharath Party (PPRP) MP.
It called for coalition and opposition MPs and senators to study all six bills for one month before reconvening in November to vote again on whether the bills are to be accepted at their first reading.
Originally, the joint sitting was due to vote on whether to accept the six bills yesterday.
Virat Rattanaset, chief government whip, said it would be best if lawmakers from all parties sat down for talks for 30 days than simply rejecting the bills, which was also a possibility.
Sutin Klungsang, chief opposition whip, disagreed, saying the committee was a waste of time, and there was no guarantee the Senate will eventually accept the six bills in the first reading.
"It would have been better to vote and decide on the fate of the bills [yesterday] rather than spending a month studying them," Mr Sutin said.
According to the opposition, if parliament does not vote on the drafts next month, it will have to wait until May to submit a new draft. That has given rise to claims by some critics that the decision to set up the committee is really a ruse and an eventual decision will be made to give the bills the axe.
Mr Sutin noted that if the six bills cannot pass the first parliament reading, the charter amendment proposed by Internet Law Reform Dialogue (iLaw), an NGO, is also likely to be rejected in parliament because it shares similar principles listed in the versions endorsed by opposition parties.
According to iLaw, 100,732 people have signed their names in support of its version of the charter amendment bill. On Tuesday, House Speaker Chuan Leekpai said iLaw's version could not be scheduled for parliamentary discussion now as it has to wait until the next House session in November.
Senators yesterday insisted any proposal for the setting up of a charter drafting assembly, which is required before a new constitution can be written, must be put to a public referendum so citizens can decide what they want in a new charter.
Senator Tuang Antachai told parliament the setting up of a new charter drafting body can only proceed after receiving public backing. He said he believes if the suggestion is ignored, someone will petition the Constitutional Court to rule on the matter.
Gen Somjate Boonthanom, another senator, said proposals to amend Section 256 of the constitution to remove Senate powers will lead to a "parliamentary dictatorship". He was referring to one of the demands made by student activists as part of the constitution rewrite.