Signs of a rift have appeared between the Pheu Thai Party and Future Forward MPs after the latter were denied the chance to grill Deputy Prime Minister Prawit Wongsuwon and Interior Minister Anupong Paojinda in the censure debate.
Piyabutr Saengkanokkul, former secretary-general of the now-dissolved Future Forward Party, took to Facebook to criticise the main opposition party and claim his MPs had been "cheated" of their debate time to save Gen Prawit's skin.
His criticism came after the opposition's request for more debate time was denied by Deputy House Speaker Supachai Phosu on Thursday evening.
Mr Piyabutr said the censure debate was plagued with trouble from the start, following rumours of a request to omit Gen Prawit from scrutiny. Future Forward insisted on grilling Prime Minister Prayut Chan-o-cha and four cabinet ministers including Gen Prawit.
"There was a proposal that only Gen Prayut should be censured. We stood our ground and insisted that the other ministers must also be scrutinised because all the preparations had been made," he wrote.
Gen Prawit eventually appeared on the list of censure targets, but only after it had been changed several times.
Mr Piyabutr said the opposition partners failed to reach an agreement on how to divide the debate time. The FFP wanted to scrutinise Gen Prawit after the prime minister and wanted 11 hours for its speakers, but Pheu Thai proposed that Gen Prawit should be the last minister grilled.
After one and a half days of debate, government and opposition whips finally agreed to discuss the time sharing, but no Future Forward MP was invited, he said. It was agreed the government would get 10 hours and the opposition 21 hours.
But Mr Piyabutr criticised opposition whips for not considering how many opposition MPs had yet to speak. He noted that Future Forward MPs were supposed to get almost nine hours of debate time.
It was agreed the debate's first three days would focus on Gen Prayut and the last day on the five cabinet ministers, according to Mr Piyabutr. That agreement was torn up when a Pheu Thai MP failed to show up on the third night but insisted on using up debate time the following day.
Mr Piyabutr said the party had consulted Pheu Thai leader Sompong Amornvivat and other senior party figures, but to no avail.
Future Forward MPs then decided to grill Deputy Agriculture and Cooperatives Minister Thamanat Prompow and Gen Prayut on the third night, as suggested by the Pheu Thai Party.
On the final day of the debate, the Pheu Thai MP in question arrived late and used up the other speakers' time while cabinet ministers took several hours answering questions.
"I know that 'they' didn't want us to scrutinise the remaining ministers, especially Gen Prawit," Mr Piyabutr wrote.
"They burned our time and the government seized the opportunity and refused to compromise [by granting more debate time] because they wanted to protect Gen Prawit. We had to stage a walk-out and speak outside parliament."
"We were fully prepared for the debate, but we were denied by inefficiency and a lack of respect for the rules. The censure motion was the opposition's crucial motion but we were cheated of debate time."
He warned that politics outside parliament would intensify if the public lost faith in MPs.
Suthin Klangsaeng, opposition whip chief and Pheu Thai MP for Maha Sarakham, apologised on Friday for a "miscalculation" of time allotted to opposition parties.
He denied it was a tactic to protect Gen Prawit and Gen Anupong from being grilled by Future Forward.
"We reached an understanding on key principles but need to talk to them about details," he said.
Chawalit Wichayasut, deputy leader of the Pheu Thai Party, denied the allegations that his party betrayed the opposition, saying what happened on the last day of the censure debate was "beyond expectation".