Executive members of the Sang Anakot Thai agreed on Wednesday to offer the party chair to former deputy prime minister Somkid Jatusripitak, who has applied to join the party.
Party leader Uttama Savanayana said a meeting of the party executive agreed unanimously to invite Mr Somkid to be chairman when he attends a key party meeting on Thursday, as the party gears up for the coming general election.
They displayed Mr Somkid's approved membership application.
The decision was highly expected, after Mr Somkid resigned from all positions at Saha Pathana Inter-Holding (SPI) Plc and applied for party membership.
Mr Somkid is strongly tipped to be the party's candidate for prime minister. A formal announcement could be made at the meeting on Thursday.
Mr Uttama and party secretary-general Sontirat Sontijirawong previously worked for Mr Somkid under the Palang Pracharath Party banner in the current government. All left amid conflict within the ruling govrnment party.