The fate of the 3.2-trillion-baht budget bill is thought to lie in the hands of some 10 opposition MPs, who are expected to abstain from Saturday's vote and allow the bill to pass its first reading.
The three-day budget debate is scheduled to wrap up today with a vote that's seen as a contest of strength between the Palang Pracharath Party (PPRP)-led coalition government and the Pheu Thai-led opposition.
The government bloc currently has 253 MPs while the opposition camp has 243, though it is traditional for the House speaker and deputies to abstain from voting. A defeat in the budget bill vote would put the government under pressure to step down or dissolve the House.
A source in the PPRP said on Friday the budget bill is likely to pass its first reading without a hitch thanks to support from ruling coalition partners and "help" from 10 opposition MPs.
According to the source, most of these helpers are expected to abstain and some may even vote for the bill.
"It will sail through the first reading and there shouldn't be any problem in the second and third readings either," said the PPRP source.
However, the source said Future Forward Party MPs are highly likely to reject the draft bill.
A source in the Pheu Thai Party admitted that opinions are split among the opposition parties on whether they should abstain, which would be in accordance with political tradition, or reject the budget bill.
The seven-party opposition will meet on Saturday around noon to discuss how its MPs will vote, the source said, while noting that renegade Future Forward MPs might vote in favour of the bill.
"This is the first reading only. The budget bill will be vetted by the House committee when the budget allocation is revised. The real showdown will be in the third reading," said the source.
Khrumanit Sangphum, a Pheu Thai MP for Surin, said his party's MPs have yet to decide on the budget bill. However, he said the draft law concerns public spending which affects the people's and the country's well-being, so the decision should be based on the people's best interests.
"The budget bill is about people and the nation's problems. It is not a no-confidence debate," he said.
A source in the Bhumjaithai Party said Future Forward should be watched closely in the vote after three of its MPs rebelled against the party line and voted to accept an executive decree on the transfer of army units to royal command.
The source said all Bhumjaithai MPs will toe the party line and vote for the budget bill.
Nine micro parties and two independent opposition parties have also pledged their support.
Rawee Maschamadol, leader of the ruling coalition's New Palang Dharma Party, said all nine micro parties will vote for the bill because they see it as crucial tool to drive the country.
Phichet Sathirachawal, leader of the Prachathamthai Party, said he and Thai Civilised Party leader Mongkolkit Suksintaranont will vote for the bill in the first reading. Both parties have declared themselves independent opposition members.
Jaruek Sri-on, an FFP MP for Chanthaburi who on Thursday voted in favour of the executive decree, declined to say how he would cast his vote today.
Meanwhile, Yutthapong Charasathien, a Pheu Thai MP for Maha Sarakham, on Fridaydropped a bombshell during the budget debate by alleging an illegal casino was operating in Bangkok's Silom.
The MP said the casino's location came under the jurisdiction of either Bang Rak or Thung Maha Mek police and called on Prime Minister Prayut Chan-o-cha to launch a probe. Bang Rak police denied the allegation.