The opposition intends to file a censure motion against Prime Minister Prayut Chan-o-cha over his handling of the Covid-19 pandemic.
It will also push for an extraordinary session of parliament if a censure debate cannot take place during the current parliamentary session due to the pandemic.
Yutthaphong Charassathien, chairman of the main opposition Pheu Thai's censure debate panel, said on Tuesday the party had initially planned to submit the debate motion before the New Year.
He now expected it to be submitted to House Speaker Chuan Leekpai in mid-January, or at the latest by the end of the month.
The censure debate would focus on the failure of the government, the prime minister in particular, to deal with the Covid-19 crisis, he said.
He gave no details about how the government had failed in its duty.
Several ministers would also be censured for causing damage to the country, he said.
Sutin Klungsang, the opposition's chief whip, also from Pheu Thai, said the party was concerned that a censure debate might not be able to take place during the current parliamentary session.
He also said the opposition would submit a censure debate motion before the end of this month.
Mr Sutin suggested parliament extend the current session or approve an extraordinary session if a censure debate can't be held in time.
However, Mr Chuan said an extraordinary session to censure the PM was unlikely.
The opposition had until Feb 28 -- the last day of the current session -- to submit a censure motion, he said.
Asked what would happen if the opposition submitted the motion by Feb 28 but parliament was still unable to convene due to the pandemic, Mr Chuan said an extraordinary session might be possible at that stage.
Mr Chuan invited all parties to a meeting on Monday to discuss the impact of Covid-19 on meetings of the committee debating charter amendments.
As for other committees, Mr Chuan said parliament would complete amending its regulations on electronic meetings by the end of this week so all the meetings can be held online.
The cabinet on Tuesday approved a draft royal decree proposed by the Cabinet Secretariat to close the ordinary session of parliament from March 1, government spokesman Anucha Burapachaisri said.
