A charter amendment bill was rejected by the parliament in its third and final reading late on Wednesday night, failing to get the support of a majority of parliament members and at least one-third of senators as the constitution required.
The bill received votes of support from 206 House representatives and two of the 250 senators, while half of the current joint parliament is 367 (there are by-elections pending for vacant seats).
Four senators voted against the bill and 10 representatives and 84 senators abstained. Nine representatives and 127 senators chose "no vote".
The constitution also requires a constitutional bill to have the approval of at least one-third, 84, of the senate.
MPs of coalition party Bhumjaithai walked out of the joint sitting. Chada Thaiset, deputy leader of the party, said he was disappointed with the voting, which reflected a political strategy and made earlier deliberations and the first two readings of the bill a waste of time.
He said that given the recent Constitutional Court ruling, the parliament could have shelved the bill and organised a referendum before proceeding with the third reading if people agreed to charter changes.
MPs from the Chartthaipattana Party also walked out. Party MP Nikorn Chamnong said the parliament should have kept the charter amendment bill.
House Speaker Chuan Leekpai earlier on Wednesday night ordered the parliament to go ahead with a vote on whether to pass the bill after an 11-hour debate.
The move came after MPs and senators voted 473:127 in favour of a motion put by deputy leader of the Palang Pracharath Party Paiboon Nititawan that parliament follow its agenda and vote.
Parliament had been stuck in limbo on Wednesday during an extraordinary session convened to debate the fate of the bill. The session was initially called to scrutinise the bill in its third and final reading, but a full version of the Constitutional Court ruling caught members by surprise.
The court said that while parliament had the power to draw up a new charter, those with the power to establish it must first decide by referendum whether they wanted a new constitution. And if those people decided they wanted a new charter and a draft was duly completed, another referendum must be held for the people to endorse it.
On Tuesday, parliament's legal team suggested suspending the final reading pending a referendum on whether it should mandate parliament to write a new charter.
Mr Chuan kicked off the meeting by informing the joint sitting of MPs and senators of the court ruling before letting them debate the next course of action. Several motions were put forward.
Senator Somchai Sawaengkarn proposed a motion calling for parliament to drop the final reading, while others including Democrat leader Jurin Laksanawisit said the Constitutional Court should be asked for further clarification.
Mr Jurin said several points needed clarifying such as the referendum process and the status of the bill. The opposition, meanwhile, wanted to push ahead with the third reading.
