Gen Wit Devahastin na Ayudhya on Monday became the leader of a small party now renamed the Thailand Together Party.
The party, formerly known as the Thai Nation Power Party, held a special general meeting at Rama Gardens Hotel on Monday.
The party elected a new executive board of 14 people, including Gen Wit as leader and veteran politician Chamlong Krudkhunthod as secretary-general. Mr Chamlong is a former election candidate of the ruling Palang Pracharath Party (PPRP).
Gen Wit said the Thailand Together Party had only one MP. He had to return to politics because he had to find a new party for the politicians who followed him out of the Setthakij Thai Party.
Gen Wit was considered a close aide of Deputy Prime Minister and PPRP leader Prawit Wongsuwan and was forced to resign as the leader of Setthakij Thai. He was succeeded by Thamanat Prompow, who has refused to support the government. Mr Thamanat was also close to Gen Prawit.