The lawmakers gave well-prepared performances in the three-day House debate on the 3.2-trillion-baht budget bill for the 2020 fiscal year, according to academics.
Yutthaporn Isarachai, a political scientist from Sukhothai Thammathirat Open University, said the budget debate marks major development in the parliamentary system, with the presence of diverse groups of representatives.
Mr Yutthaporn heaped praise on the opposition parties for proposing criteria to decide whether they should vote for or against the budget bill, saying it is another step forward for good governance.
"In the big picture, the debate is a lot better than the previous ones. Several MPs stick to facts and information and do not stray out of the debate on fiscal policy.
"It's totally different from the previous proceedings on the selection of the prime minister and government policy statement," he said.
"I think the House of Representatives has elevated itself."
However, he noted that speeches given by some government MPs failed to address the overall spending plan because they focused more on the individual ministers associated with their parties or political factions.
According to Mr Yutthaporn, Prime Minister Prayut Chan-o-cha's performance stood out, as he took the opposition's questions head-on in and in a level-headed manner.
In his opinion, the budget bill would pass its final reading without needing the help of the so-called "cobra" MPs who broke away from the opposition to vote for the legislation.
He pointed to Section 143 of the constitution, which requires the MPs to complete their deliberations of the budget bill within 105 days of the bill having been adopted in its first reading, or the draft law will be considered "approved" before it is forwarded to the Senate for scrutiny.
"The renegade [cobra] MPs are more like a backup plan, in case the government can't control coalition partners," the political scientist said.
Wanwichit Boonprong, a political science expert with Rangsit University, said both sides did their homework and kept their discussions to the point instead of exchanging sharp jabs or forceful rhetoric.
He said several MPs from the Future Forward Party displayed a good understanding of the budget plan and that Gen Prayut had shown improvements and adjusted himself well to the elected chamber.
The academic said House Speaker Chuan Leekpai and his deputies were also efficient in keeping the MPs in order and making sure their discussions stayed on course.
Meanwhile, Pheu Thai secretary-general Anudith Nakhornthap said that while he was satisfied with the opposition MPs' work, he was disappointed with the government.