Prime Minister Prayut Chan-o-cha said he is considering a move to join the newly-established United Thai Nation Party (UTN) or Ruam Thai Sang Chart.
He spoke about the matter for the first time on Wednesday.
Asked by reporters whether he had applied for party membership, Prayut said: "I am still considering it.''
He refused to comment when pressed for an answer on his political future. He only said: "It will become clear next year.''
UTN's leader, a former Democrat MP, on Wednesday denied Prayut applied for party membership on Monday.
The UTN was founded in March last year by a former aide to the prime minister, to back Prayut's return as PM after the next election, if he so wishes.
The likelihood of Prayut moving to the UTN gained momentum after he reportedly met Deputy Prime Minister Prawit Wongsuwon, the PPRP's leader, in Bangkok last Sunday.
Prayut is believed to have informed Prawit of his plan to switch parties ahead of the coming general election.
A PPRP MP said several party MPs were considering whether to stay put or defect to the UTN.
If Prayut is re-elected by parliament as prime minister after the next election expected in the first half of next year, he could only serve as PM for another two years as his premiership will end in 2025.
