Fears about risks to the economy are growing after 174 MPs on Wednesday requested a Constitutional Court ruling on the validity of the 3.2-trillion baht budget bill for the 2020 fiscal year.
The fears stem from a former Democrat Party MP claiming that two Bhumjaithai MPs cast votes in favour of the bill without being present in the House.
House Speaker Chuan Leekpai said on Wednesday that submission of the budget bill for royal endorsement will have to wait until the court rules on its validity.
Deputy Prime Minister Somkid Jatusripitak admitted that any further delay to its enactment will have a major impact on the country's economy. He said the Finance Ministry, state agencies and state enterprises have been instructed to come up with back-up plans to deal with any problems if the bill is ruled invalid.
Although also admitting that the case may delay enactment of the budget bill, Deputy Prime Minister Wissanu Krea-ngam said he did not think it would cause any major damage.
A group of 90 coalition MPs have submitted a request -- through Mr Chuan -- for the court's ruling on the bill's validity following the voting irregularity revelation.
In the petition, the court is asked to rule on whether an MP voting on behalf of other MPs violates Section 120 of the constitution, which stipulates that each MP has one vote, said chief government whip Wirat Rattanaset.
If voting on behalf of other MPs constitutes a violation, coalition MPs want to know whether the whole bill will be invalid or just the sections that the offending MP voted on.
If the whole bill becomes invalid, they also want the court to decide if Section 143 of the constitution will be applied in this case.
The section stipulates that if the House of Representatives cannot finish deliberating the budget bill within 105 days of it reaching the House, the bill shall be deemed to have been approved.
Meanwhile, 84 opposition MPs on Wednesday also submitted their own request for a Constitutional Court ruling on the budget bill's validity through Mr Chuan.
Mr Chuan said on Wednesday that the bill, which was endorsed by the Senate on Tuesday, was supposed to be forwarded to Prime Minister Prayut Chan-o-cha, who has five days in which to submit it for royal endorsement.
The House Speaker said that it is important for all involved to clear any doubts about the bill's validity before it is submitted for royal approval. Mr Chuan said he had already received the findings of a probe into the matter from House secretary-general Sorasak Pienvej.
The irregularity was revealed by former Democrat Party MP Nipit Intarasombat, who said Chalong Therdwirapong, a Bhumjaithai MP for Phatthalung, was not in the chamber when his votes were registered on Jan 10-11.
On Monday, Mr Chalong admitted he had left the House to attend a funeral in Phatthalung on Jan 10 and forgot to take his electronic voting card with him.
Mr Nipit also claimed on Wednesday that Natee Ratchakitprakarn, another Bhumjaithai MP, also voted for the bill without being present in the House.
He showed an air ticket and a picture of Ms Natee passing through an immigration checkpoint at Suvarnabhumi airport to board a plane to China, at the same time her vote for the budget bill was cast.
The Constitutional Court had previously ruled against a 2-trillion-baht loan bill proposed by the Yingluck Shinawatra government, branding it unconstitutional, after reports emerged some Pheu Thai MPs used voting cards on behalf of their colleagues, Mr Nipit said.