House Speaker Chuan Leekpai confirmed on Thursday the general debate on the incomplete oath recital by Prime Minister Prayut Chan-o-cha will proceed as planned, saying it is part of the checks-and-balances process.
He said the Constitutional Court's dismissal of a petition involving the oath controversy had nothing to do with the House, which is obliged to scrutinise the performance of the government.
"In the general debate, MPs can discuss, ask questions and give suggestions to the government, as a part of the constitutional checks-and-balances process," he said.
In dismissing the petition, the court said the swearing-in ceremony is a political issue concerning the cabinet and the monarchy.
It was beyond the jurisdiction of the court to examine issues between the administrative branch and the monarchy.
Gen Prayut took the oath before His Majesty the King on July 16. The prime minister failed to complete the oath, as he omitted the final sentence during the swearing-in, upsetting his critics in parliament.
The petition was lodged through the Office of the Ombudsman on Aug 20 by Panupong Churak, a Ramkhamhaeng University student, who cited Section 213 of the charter on the right of citizens to complain if they consider their constitutional rights are being violated.
The court's rejection of the petition has stirred speculation the debate might be cancelled.
Deputy Prime Minister Wissanu Krea-ngam said on Thursday that while he doubted the court deliberately ruled in favour of the government, he considered the oath controversy to be over.
According to Mr Wissanu, the oath controversy is unlikely to be submitted to other independent agencies for consideration, based on the court's ruling.
The opposition said on Thursday the court's decision gives the House a more solid reason to grill the government over the oath controversy and keep its performance in check.
Future Forward Party secretary-general, Piyabutr Saengkanokkul, said the court's explanation clearly points out the oath gaffe is a political issue which gives the House the justification it needs to proceed with the debate.
He said the Opposition has yet to assign debate time slots, nor selected speakers for the debate, which is expected to run for 10 hours.
It is not known what issues critics intend to raise in the debate.
The opposition's chief whip, Suthin Khlangsaeng, concurred with Mr Piyabutr and said on Thursday that the House has all the reason to proceed with the scrutiny, following the court's decision.
Meanwhile, Pheu Thai MP for Nan, Cholnan Srikaew, said the general debate can proceed simultaneously with the reading of the court's ruling on the qualifications of Gen Prayut as a prime ministerial candidate.
The court is scheduled to issue its ruling on Sept 18 at 2pm.
The ruling is a response to the opposition's petition on Gen Prayut's qualifications, which was forwarded by the Mr Chuan.
The petition alleges that Gen Prayut, in his past capacity as National Council or Peace and Order chief, was considered a state official and so ineligible to be premier after the election.
Dr Cholnan said the ruling on Gen Prayut's candidacy status has nothing to do with the oath debate, even if the court rules against him.
"If the court rules that he was indeed eligible for office, we will hold it against him because he always said he is ratthathipat [supreme authority]," he said.
"The remark shows his lack of respect for the charter and we want to show that."
Earlier, the Office of the Ombudsman ruled Gen Prayut, in his capacity as head of the NCPO, was not a state official.