There is a plot to sabotage this week's general debate in which cabinet ministers will be grilled on their performance in an effort to avoid scrutiny, said deputy government whip Chinnaworn Bunyakiat.
The Democrat Party MP for Nakhon Si Thammarat said he was contacted by someone who wanted to see the general debate set to take place on Wednesday and Thursday collapse.
He said the debate will take place anyway, he insisted, as it is an important forum to gauge the opposition's opinion on the government's performance.
If the debate is aborted for any reason, it would have a negative impact on the government's reputation.
"Anti-government elements will have a field day politicising the issue," he said, urging all parties to attend the debate, though ultimately it would be up to the coalition parties whether they will participate in the session.
His remark comes amid criticism over the frequent collapse of parliament sessions due to lack of quorum, as many MPs, mostly from the government coalition, have started to resign to join other parties for the next election.
The opposition on Sunday said it was concerned the lack of quorum could end the debate prematurely. However, the session will only be suspended on the day the quorum problem occurs.
Mr Chinnaworn said the Democrat Party is ready to join the debate. The ruling Palang Pracharath and Bhumjaithai parties have told him they also will take part.
The opposition had earlier said the debate, with no censure vote to be cast, will expose the government's administrative irregularities. The bloc added the session will not bode well for the coalition's election prospects.
Expected to be grilled are Digital Economy and Society (DES) Minister Chaiwut Thanakamanusorn, Deputy Prime Minister and Public Health Minister Anutin Charnvirakul, Transport Minister Saksayam Chidchob, and Deputy Prime Minister and Commerce Minister Jurin Laksanawisit.
Others in the line of fire are Finance Minister Arkhom Termpittayapaisith, Labour Minister Suchart Chomklin and Deputy Prime Minister and Energy Minister Supattanapong Punmeechaow.