The government and opposition parties will have separate meetings on Tuesday as they gear up for Thursday's debate on the 3.2-trillion-baht budget bill for the fiscal year 2020.
The vote on the budget bill will be a high-stakes battle between the Phalang Pracharath Party (PPRP)-led coalition government, which currently has 251 MPs, and the Pheu Thai-led opposition, which has 244 MPs.
The government risks being forced to dissolve the House or step down if it loses the vote.
Chief opposition whip and a Pheu Thai MP for Maha Sarakham, Suthin Khlangsaeng, said on Monday that the opposition whips will on Tuesday meet for talks with representatives of the Budget Bureau and state revenue collection agencies.
The seven opposition parties were doing their homework to prioritise issues and about 90 speakers will be lined up for the debate, Mr Suthin said, adding that 60 of them will come from Pheu Thai.
He said the opposition will receive about 20 hours for the debate and Pheu Thai will be given about 670 minutes in total while other parties will be allotted time depending on the number of MPs they have.
Pheu Thai speakers will be given seven to eight minutes each as party leader Sompong Amornwiwat, who will be the first speaker, will speak for about 30 minutes, Mr Suthin said.
Asked what Pheu Thai will do to prevent renegade MPs from voting in favour of the budget bill, Mr Suthin said the party has no measure to punish those "cobra" MPs, but it will be left to voters to do this.
However, he said there are no renegade MPs within the party and all opposition MPs will toe the line.
Future Forward Party spokesperson Pannika Wanich said the party will meet and conclude on Tuesday on the speakers.
In another development, the leaders of two small parties which earlier withdrew from the coalition government and now call themselves "independent opposition" said they will on Wednesday ask House Speaker Chuan Leekpai to give them 5-10 minutes each to debate the bill.
Mongkolkit Suksintaranont, leader of the Thai Civilised Party, said the move came after he and Pichet Sathirachawal, leader of the Prachatham Thai Party, requested their share of time for the budget grilling from both the seven-party opposition bloc and the coalition camp.
However, the opposition bloc laid down a condition that the small parties must vote against the bill, while the coalition wants them to vote in favour as a condition, Mr Mongkolkit said while insisting that the small parties would have their own discretion in the vote.
He said his questions in the debate will take aim at the budget allocation proposed by the Defence Ministry, saying he intends to curtail the military's arms procurement spending.
Mr Mongkolkit said the armed forces should cut out middlemen and deal directly with manufacturers, which would help reduce commission fees by 30-40% and this would help the armed forces buy cheaper weapons.
Suchart Chomklin, a PPRP member of parliament for Chon Buri, said that even though the government sits on a razor-thin majority in the House, he was confident that all coalition MPs will vote for the bill.
Government whips will see to it that all government MPs attend the budget debate and are present when a vote is called, said Mr Suchart who is chief of the party MPs.
He added that the so-called independent opposition parties should understand what will benefit the country and not oppose everything without good reasons.
Ongart Klampaibul, deputy leader of the Democrat Party, said the Democrat MPs will on Tuesday meet to discuss preparations for the opposition's grilling on the budget bill.
Mr Ongart said he believed the budget will pass the House despite the government's slim majority, adding that the bill is crucial for steering the country forward.