House Speaker Chuan Leekpai on Wednesday warned of dire political consequences if the 2020 fiscal budget to be tabled in parliament on Oct 17 is shot down due to the razor-thin majority of the coalition government.
Mr Chuan said the government whips would have to ensure passage of the 3.2-trillion-baht spending plan, adding they were likely aware of what would follow if the bill did not pass.
While Mr Chuan did not elaborate, the bill's failure would likely result in political chaos. Prime Minister Prayut Chan-o-cha could resign or dissolve the House and call a snap election, political experts said.
The House speaker said he had no objection to the opposition's plan to seek a five-day debate on the budget bill, but he expected MPs to keep their discussions concise.
Suwat Liptapallop, chief adviser to the Chartpattana Party, said the government would talk to its coalition partners to make sure they understand why a vote on the budget bill is crucial and that they must get on board.
Mr Suwat said with the global economic slowdown and Thailand's major trading partners facing an economic crunch, investment funds in the budget bill would help stimulate the economy.
Of the 3.2 trillion baht requested, the investment budget in fiscal 2020 stands at 655 billion baht, accounting for 20.5% of the total.
According to Mr Suwat, the government's stability is still dependent on the unity of its coalition partners as well as public confidence in the government's performance.
He admitted the new election rules make it hard to form a stable government which faces the challenging task of keeping all coalition partners in line and voting in support of key bills.
Pheu Thai chief strategist Khunying Sudarat Keyuraphan said the party is collecting evidence in a bid to take legal action against those attempting to lure opposition MPs into their fold to ensure the bill's passage.
"We're not bluffing [about the legal action] and we hope the evidence is enough," she said.
According to Khunying Sudarat, a group of Pheu Thai MPs met key government figures on Sept 18 when the parliamentary debate on Gen Prayut's oath-taking mistake took place and received offers to switch camps.
She said she learned about the meeting from those MPs and expressed confidence they would not defect.
Sira Jenjaka, a Palang Pracharath Party (PPRP) MP for Bangkok, challenged Khunying Sudarat to produce evidence to support her accusations about MP-buying while accusing the Pheu Thai figure of making up a story to discredit the government.
Mr Sira said MPs could not switch parties after the election and if Pheu Thai MPs voted in favour of the government over crucial legislation they would be protecting the public interest.
Government chief whip Wirach Ratanasate denied comments by PPRP figure Thamanat Prompow that Deputy Prime Minister Prawit Wongsuwon was in charge of the talks with possible renegade MPs.
Mr Wirach said Gen Prawit, the party chief strategist, has nothing to do with the issue and Capt Thamanat's remarks could have stemmed from a misunderstanding.
Gen Prawit on Monday said the PPRP had no policy to "fish" for opposition MPs, but it would be helpful if they voted in support of the government.
Future Forward Party leader Thanathorn Juangroongruangkit said on Wednesday he has strong evidence to attest to his innocence in cases against him concerning media shares and a loan he gave to his own party.
He insisted the allegations were being drummed up to paint a picture of his party being at risk of dissolution so rivals could poach his party's MPs.