As the bill returns to the House for its second reading today, Ms Yingluck, accompanied by Deputy Prime Minister and Finance Minister Kittiratt Na-Ranong, met members of Thai Bankers' Association Wednesday evening over dinner.
As the loans will mainly be taken out domestically, local banks would play a key role in the plan.
Government spokesman Teerat Ratanasevi said the prime minister told the bankers about the necessity of the bill to fund mega-transport projects over the next seven years that should open up new opportunities for the country's economy.
Ms Yingluck said the the need to enact the bill, instead of using the annual budget, is for the sake of project continuity.
Most of the bankers support the borrowing bill, Mr Teerat said.
Early in the day, Mr Kittiratt said he was confident that the government's 2-trillion-baht loan bill will pass its second and third readings in the House.
Mr Kittiratt said it was a fiscally disciplined proposal that had been carefully considered and produced by the book.
The government would let the more than 100 MPs scheduled to air their reservations about the bill to have their full say, he said.
Even if the bill is taken to the Constitution Court, the government would be ready with explanations, he added.
According to Mr Kittiratt, the bill will not raise Thailand's public debt above 50% of GDP. The public debt ceiling under national standards for fiscal discipline is currently set at 60% of GDP. (Story continues after photo)
Besides, the actual borrowing for each project will take place after relevant organisations scrutinise the project and seek approval from cabinet, Mr Kittiratt said.
He denied that the 2-trillion-baht sum will be borrowed all at once, as was the case with the previous government led by the Democrat Party for its Thai Khem Khaeng economic stimulus package.
"As the finance minister proposing the bill, I see no reasons for any objection to it," Mr Kittiratt said.
The only reason for the loan bill to be rejected would be if it is found to violate the constitution, Mr Kittiratt said.
"If it is rejected, I think there are ways out. But if it is dropped, it will be a pity and have impacts on macroeconomic management," he said.
The Democrat Party on Wednesday promised a tough onslaught when the House resumes debate on the borrowing bill - but they lack the numbers to really make any difference.
Opposition leader Abhisit Vejjajiva said that Democrat MPs are fired up to challenge the government on the bill in the second reading debate, set for Thursday and Friday.
The party's main arguments are that there is no need for the Pheu Thai Party-led government to borrow money from outside to fund the projects, because the state coffers could fund them through the annual budget, and that many projects are vague in detail, or even have no details at all, and are wide open to corruption.
Mr Abhisit also expressed a new concern, that the government's tax receipts could miss the target and be unable to service the long-term loans, plus interest, for the projects.
More than 100 Democrat MPs are lined up to speak on the bill, raising the question whether they can all be accommodated in the two days allotted the debate.
Opposition chief whip Jurin Laksanavisit Wednesday urged the government to let MPs speak their mind on the bill if they intend to respect the rights of minority parties.
With its majority in the House, the government would be able to pass the bill anyway, he said.
"I warn the government MPs not to propose closing the debate when opposition MPs who have reserved their rights to debate have yet to speak, otherwise it will violate the constitution and the [Democrat] Party will petition the Constitution Court," he said.
Mr Jurin was referring to the strategy used by ruling Pheu Thai MPs during the recent debate on the charter amendment bill.
A total of 143 MPs intend to voice their reservations on the loan bill.
About 80% of them are opposition MPs. The opposition has argued that the government can implement its transport projects without the loan bill by using its annual budget, which would not violate the constitution.