The main opposition People's Party (PP) said it will petition the Constitutional Court seeking the removal of Deputy House Speaker Pichet Chuamuangphan for allegedly misusing parliamentary funds.
The move, announced by the party's Bangkok MP Bhuntin Noumjerm, followed a recent House debate on the 2026 fiscal budget bill, during which Mr Pichet, a Pheu Thai MP for Chiang Rai province, was accused of initiating budget proposals that may involve irregularities.
According to Mr Bhuntin, during the budgeting process for the 2025 fiscal year, Mr Pichet reportedly instructed his team to draft four parliamentary affairs project proposals worth 443 million baht for the Secretariat of the House of Representatives to seek funding for.
The proposals reportedly raised concerns from both the Office of Policy and Planning and the Office of Finance, which warned these projects did not follow all the relevant laws and parliamentary regulations, with the spending deemed to be in violation of Section 144 of the constitution.
Section 144 prohibits members of the House from altering or adding items or amounts to the budget bill in ways that result in the direct or indirect misuse of budgetary funds.
After being informed of the concerns, Mr Pichet reportedly revised the plan, replacing the original proposals with three parliamentary seminar projects worth 350 million baht.
According to Mr Bhuntin, more than 2,200 seminars were scheduled to take place within a year under this revised proposal.
Although the cabinet initially slashed the budget for the seminars to 83 million baht, Mr Pichet later succeeded in increasing it to 178 million baht during the parliamentary budget review.
This would allow for about 1,300 seminars to be held in a year, or an average of four per day, the opposition MP said, adding that after the budget was approved, several requests for seminars were concentrated in Chiang Rai.
"This kind of spending doesn't serve the public. It suggests corruption. The House is supposed to scrutinise the budget, not misuse it," he said.
Mr Bhuntin also claimed that over 50 million baht was diverted to fund landscaping work and related expenses within the parliamentary compound, under Mr Pichet's supervision.