The Constitution Court yesterday rejected a petition asking it to rule on the legality of the government's proposed charter amendments and to issue an injunction suspending debate on the bill.
The petition had been submitted by the Network of Volunteer Citizens to Protect the Three Institutions, led by Boworn Yasinthorn. The group claimed the charter change bill could violate sections 68 and 291 of the constitution.
Section 68 deals with acts that could undermine the constitutional monarchy or seize power through unconstitutional means.
Section 291 prohibits charter amendments that would change the structure of the state.
The group argued the charter amendment bill, which would make major changes to the composition of the Senate, would change the structure of parliament, thereby possibly leading to changes in the state structure.
The group had also asked the court to consider dissolving political parties which have supported the bill.
However, the charter court threw out the petition with a vote of seven to one.
The court said the petition's claim that the bill violates Section 68 of the charter had no grounds, and there was therefore no need for the court to consider the other issues.
Meanwhile, government chief whip Amnuay Khlangpha said yesterday the government, opposition and Senate whips would try to ensure that debate on the 13-section charter change bill was wrapped up by late last night.
The joint parliamentary session yesterday began deliberation on Section 10 of the bill.
Mr Amnuay said the government whips had discussed the issue with opposition deputy chief whip Yala Prasert Pongsuwansiri.
They agreed the parliament president must strictly enforce House regulations to keep the debate on track.
Mr Amnuay said after parliament finishes the second reading of the bill, lawmakers must vote on the third and final reading within 15 days.
Opposition whip chief Jurin Laksanavisit denied the opposition was using filibuster tactics to prolong the debate.
If the parliament president and his deputy do not deny the opposition the right to debate, the meeting should go smoothly, he said.
Mr Jurin criticised Senate Speaker Nikom Wairatpanich for being biased in his moderation of recent sessions.
He said Mr Nikom has a conflict of interest as he had signed in support of the charter amendment bill but was still acting as chairman of the joint sessions.
Parliament last night voted to pass Section 11 regarding the timeframe of the Senate election by 343 votes to 11 while there were 25 abstentions.