The government comfortably survived a no-confidence vote on Saturday even as commotion opened on another front concerning secret payments to small parties.
Setthakij Thai Party leader Thamanat Prompow alleged some small parties had pocketed monthly allowances over the past three years. Some MPs received 100,000 baht per month, a source said.
Capt Thamanat's claims attracted the attention of political activists who vowed to petition the National Anti-Corruption Commission (NACC) and the Election Commission (EC) for a probe.
Earlier, while he was still with the ruling Palang Pracharath Party (PPRP), Capt Thamanat introduced a phrase comparing himself to a monkey keeper feeding "bananas" to small parties to keep them loyal to the government.
If found guilty these MPs would be hit with a 10-year political ban and the parties involved in the payments could be dissolved.
On Friday, Capt Thamanat, who pulled out of the coalition government shortly before the censure debate, appeared unhappy when learning micro parties had decided to cast a vote of confidence for Prime Minister Prayut Chan-o-cha and 10 targeted ministers.
In a news interview he claimed these parties had accepted money over the past three years, which could land them in trouble. It could constitute a violation of the NACC's law that prohibits civil servants and politicians from receiving gifts worth more than 3,000 baht, he said.
The Setthakij Thai Party leader also warned the MPs who received the allowances of a leaked Line chat containing evidence of them accepting the money.
Shortly after that, Line chat messages accompanied by copies of internet banking transaction receipts were circulated. The documents suggested that a number of MPs in small parties were paid regularly.
Activist Srisuwan Janya on Saturday said he would gather information about the scandal and petition the NACC.
"Those who violate the rules will be held accountable under Section 169 of the anti-corruption law which imposes a maximum three-year jail term and/or a maximum fine of 60,000 baht. They may be held in serious violation of ethics and face a 10-year political ban," he said.
Somchai Srisutthiyakorn, member of the Seri Ruam Thai Party and an ex-EC member, said the allegations are serious enough for a party dissolution probe.
"If the party that allegedly paid those MPs is found to have violated the Political Parties Act on grounds of party manipulation, all those involved may end up being disbanded," he said.
Mr Somchai urged Capt Thamanat to file a petition with the EC.
Khathathep Techadejruangkul, leader of the Pheu Chart Thai Party, on Saturday dismissed the leaks as fabricated and said the individuals implicated in the scandal are considering taking legal action.
He downplayed the issue as nothing but a political game and said the so-called Group of 16, made up of MPs from micro-parties and several members of the PPRP, were being used by Capt Thamanat.
"He wanted the Group of 16 to do his bidding and when he couldn't, he created a fuss. There are no facts and this is a fabrication of documents. Seniors are looking into this and it will end soon," he said.
Pichet Sathirachawal, a list MP for the PPRP and head of the Group of 16, said the transactions in the leaked messages concerned the Five Provinces Bordering Forest Preservation Foundation. All questions should be directed to PPRP leader Gen Prawit Wongsuwon, chairman of the foundation, Mr Pichet said.
He said the payment was meant to cover travel expenses for small parties during their visits to the provinces, as proposed by Gen Prawit. Capt Thamanat was assigned to coordinate with small parties at that time. Mr Pichet did not know his motive but said it would not serve him well.