The opposition is considering whether to launch its first no-confidence or general debate against the government at the end of March or early April, according to the Move Forward Party (MFP).
An opposition whips’ meeting on Tuesday discussed the issue, said Parit Wacharasindhu, a Move Forward spokesman.
While a general debate does not affect the government’s survival, enough no-confidence votes would sink it.
Some unelected senators are also attempting to mount a general debate against the government, alleging shoddy state policies, before their term expires in May.
Mr Parit said the opposition, led by Move Forward, intends to use parliamentary means to keep the administration in check by pressing for an explanation of the cost-effectiveness and transparency of key government projects.
The opposition is particularly critical of the flagship digital wallet scheme and the 1-trillion-baht Land Bridge megaproject.
In addition to scrutinising government policies, the opposition plans to use the debate to highlight the value of the its agenda in pursuing important legislation.
Mr Parit also denied his party was skirting the controversy surrounding jailed former premier Thaksin Shinawatra’s hospital stay.
Thaksin was admitted to Police General Hospital on his return to Thailand on Aug 22 and has been allowed by the Department of Corrections to stay on despite reaching the maximum allowed 120 days of inpatient care on Dec 22.
Some have criticised Move Forward for going “soft” when it comes to taking Pheu Thai to task when it comes to Thaksin, who is still considered the party patriarch and a key strategist.
Mr Parit said the MFP pays equal attention to all government policies. However, the digital wallet programme entails a significant economic impact since it involves borrowing half a trillion baht to finance.
Senator Seree Suwanpanont, the chairman of the House committee on political development and public participation, said 91 senators have so far signed up in support of mounting a general debate against the government. More senators are expected to join, although some who signed up could also pull out.
The number of signatures has surpassed the minimum one-third of all senators, or 84, to back the push.
Mr Seree is among the senators who initiated the debate bid. He said the pro-debate senators expect to present their signatures to Senate Speaker Pornpetch Wichitcholchai on Friday or next Monday.
If the debate goes ahead, the senators should be given at least two days to conduct the session, he said.
Senator Direkrit Jenklongtham, deputy chairman of the Seree panel, said the government has the duty to explain its policies without delay. The Senate fears some policies, among them the digital wallet scheme, would subject the country to long-term, detrimental financial obligations.
“The debate should happen in a timely fashion to pre-empt damage or a misstep. It’s for the sake of being cautious,” he said.