Thai Raksa Chart Party lawyer Ruangkrai Leekitwattana on Tuesday handed over additional information to support his call for an investigation into the qualifications of Palang Pracharath Party (PPRP) leader Uttama Savanayana.
He claimed Mr Uttama, who is also the industry minister, is not qualified to serve as the PPRP leader because he fails to meet the criteria set out by an organic law governing political parties.
According to Mr Ruangkrai, when the PPRP held a meeting to select the party leader, Mr Uttama was neither a party member nor founder, which rendered him unqualified.
Under Section 16 of the political party law, the leader and executives of a party must be members of that same party. The Thai Raksa Chart lawyer denied he had a political agenda when he called for the investigation into Mr Uttama's qualifications. His petition was lodged with the Election Commission (EC).
PPRP executive Suraporn Danaitangtrakul claimed earlier the petition was politically motivated and insisted Mr Uttama had applied to be a party member on Oct 13.
"If I had an agenda, I'd have waited for parliament to vote to select Gen Prayut as prime minister before I filed the complaint," said Mr Ruangkrai, who defected from Pheu Thai.
Based on the comments Mr Ruangkrai made to the media last weekend, Mr Uttama was chosen as the PPRP leader in late September and he applied to be a member on Nov 13. If he is deemed to be unqualified to hold the leadership post, the qualifications of other candidates endorsed by the party would also be thrown into question, and they would most likely have to reapply.
However, election candidates are required to be party members for 90 days before election day, so to be eligible for the Feb 24 poll they must have been members of a party by Nov 26 at the latest. There are concerns that if Mr Uttama is ruled an "outsider", the PPRP may be charged for allowing others to have a say in the party's affairs, which could lead to the party being dissolved.
Mr Ruangkrai said if the EC rules against Mr Uttama, Prime Minister Prayut Chan-o-cha would have to find a new party to nominate him as its prime ministerial candidate after the poll.
"Some people may not want [Prayut] to return as premier, but I do, so he will see for himself what it's like to work under the scrutiny of the opposition," he said.