The Palang Pracharath Party (PPRP) has officially expelled 20 MPs who defected following a dispute between former party secretary-general Thamanat Prompow and present party leader Prawit Wongsuwon.
Paiboon Nititawan, the PPRP's current secretary general, announced the party's decision on Thursday after a meeting on Wednesday to formally vote to expel the 20 MPs in Thamanat's camp.
Their membership ended that day, he said.
Gen Prawit and Thamanat didn't attend the meeting. Mr Paiboon said Gen Prawit was sick.
He believed that the 20 MPs would not rush to apply for membership in other parties due to technical restrictions.
The MPs need to wait until the party has first submitted all required documents to the Election Commission, he said.
Mr Paiboon also dismissed rumours that Gen Prawit was considering stepping down and letting someone else lead the party, saying he has affirmed his intention to continue leading the party and make it win the next race with an even higher number of House seats.
Atthakorn Sirilatthayakorn, an MP for Chachoengsao and one of the 20 who were expelled from the PPRP, said the meeting went well.
He claimed that disagreements about political philosophies were the reason he and the other 19 MPs were expelled, not for any unethical or disciplinary behaviour.
He said that the group has about 30 days to find a new party to join.
Mr Atthakorn did not deny rumours that his group was considering joining the Kla Dharma Party, whose leader is Agriculture Minister Narumon Pinyosinwat, who is close to Thamanat.
More talks will be needed even though Ms Narumon has expressed her willingness to welcome the expelled MPs into her party, according to Mr Atthakorn.
Meanwhile, Ms Narumon said the party should be able to announce its decision on the 20 MPs after the New Year holiday.
She insisted that the political ideology of the 20 MPs is compatible with that of her party.
Earlier this year, Capt Thamanat and his group broke away from the PPRP, who were then offered three seats in the Paetongtarn Shinawatra cabinet, with Ms Narumon taking the agriculture portfolio and Thanadol Suwannaritr -- a close aide of Thamanat -- becoming her adviser.