Potential mass defections to the Bhumjaithai Party could trigger an early House dissolution, according to political observers.
Yutthaporn Issarachai, a political science lecturer at Sukhothai Thammathirat Open University, said that reports of 37 MPs planning to move to Bhumjaithai signal an early election may take place.
"I believe Prime Minister Prayut Chan-o-cha will dissolve the House due to several factors," he said.
First, he said, the United Thai Nation Party (UTN), also known as Ruam Thai Sang Chart, has been established to facilitate Gen Prayut's re-election bid.
The fact that the bill on political parties and the bill on the election of MPs have already cleared the Constitutional Court also paves the way for an early election, as both bills deal with how the election will be conducted, he said.
"MPs are now considering which party will give them the best chance of winning in the next election. It is only a matter of time before Gen Prayut dissolves the House," Mr Yutthaporn said.
Suvicha Pao-aree, poll director at the National Institute of Development Administration (Nida), echoed the view, saying that if Gen Prayut decides to carry on in politics, an early House dissolution can be expected.
The decision to roll out a number of economic relief measures at the end of the year was likely guided by the need to win over the public before the House is dissolved, he said.
Stithorn Thananithichot, director of the Office of Innovation for Democracy at the King Prajadhipok's Institute, said reports of defections would give parties a chance to gauge their MPs' loyalty.
"The prime minister may also be testing the waters to gauge the UTN's popularity as he wants the party to pull in as many MPs as possible. But if things do not go as planned or the party is not at an advantage, the PM may not rush to dissolve the House," Mr Stithorn said.
According to sources, some 37 MPs from various parties are expected to switch their allegiance to the Bhumjaithai Party later this week, a move which bolsters party leader Anutin Charnvirakul's chances of becoming the next prime minister.
The politicians, said to be from nine parties, will make a formal announcement on their defection to Bhumjaithai on Friday at the party headquarters, the sources said.
Bhumjaithai Party officials last week asked MPs from the Palang Pracharath Party (PPRP) who wanted to defect to send over copies of their ID cards so the party could register their membership, the sources said.
If the House of Representatives is not dissolved before its term ends on March 23, MPs have until Feb 7 to move to another party.
In this scenario, the election will take place on May 7 as announced by the Election Commission.
Political observers view the planned gathering of Bhumjaithai heavyweights led by Mr Anutin and potential candidates this Friday as the party flexing its political muscles, especially in the wake of Mr Anutin's recent remark that he would not want to inherit the prime minister's post from anyone.
The leader of the second-largest coalition party made the comment after Gen Prayut said last week he hoped to stay in office for another two years after next year's poll, during which time he would find a suitable person to succeed him once he reaches his tenure limit.
If he was re-elected, Gen Prayut would be eligible to remain in office until 2025, according to a ruling by the Constitutional Court in September concerning the eight-year limit on a prime minister's tenure.
Political observers believe Mr Anutin has a high chance of being picked by Gen Prayut as his successor.
However, the Bhumjaithai leader was quoted as saying: "For me, I have to win the trust of the people first, as opposed to waiting [to be appointed a successor]."