The Constitutional Court is to decide on Wednesday whether to hear a petition submitted last week by the Election Commission (EC) seeking a court ruling on whether Move Forward Party (MFP) leader Pita Limjaroenrat's MP status is now considered invalid, according to a source.
Another joint sitting of the House of Representatives and the Senate will also take take place to select Thailand's next prime minister.
Last week's prime ministerial vote saw Mr Pita fail to muster enough votes to become prime minister. He is accused in a number of petitions submitted to the EC to have been ineligible to stand in the election because he held 42,000 shares in iTV Plc, which is believed by some to still operate as a media company.
Former election commissioner Somchai Srisutthiyakorn, meanwhile, posted on his Facebook page on Monday his own analysis of what will happen next with Mr Pita's alleged ineligibility case.
He expected the judges to convene Wednesday morning to decide whether or not to proceed with the EC petition.
At the same time, parliament would convene to decide who will become the country's new prime minister but would spend the first half of the day debating parliament's Regulation No.41, which deals with the submission of a repeat motion, according to Mr Somchai.
He was referring to an observation made by some senators that to nominate Mr Pita for a fresh prime ministerial vote was submitting a repeat motion which is prohibited under the regulation.
Before midday, Mr Somchai said, he expects the court to agree to hear the EC's petition and suspend Mr Pita as an MP while the court looks at the case.
This will mean Mr Pita won't be able to act as an MP but will remain the MFP's sole prime ministerial candidate, said Mr Somchai.
Jade Donavanik, a legal scholar and a former constitution drafter, however, said he didn't expect to see the court decide immediately when meeting on Wednesday to suspend Mr Pita as an MP.
He said the judges will need time to contemplate the EC's petition and evidence submitted with the court before ruling if there is a need to suspend Mr Pita in case court decides to hear the case.
