About 40 MPs from various parties are expected to announce their allegiance to the Bhumjaithai Party (BJT) later this week in a move seen as bolstering its leader Anutin Charnvirakul's chance of becoming the next prime minister.
The politicians, said to be from nine parties, will make a formal announcement on their defection to Bhumjathai on Dec 16 at the party headquarters. They will join a function marking the office's reopening since renovation work started in April, sources say.
Political observers view the planned gathering of Bhumjaithai heavyweights led by Mr Anutin and potential candidates this Friday as the party flexing its political muscle, following Mr Anutin's remark that he would not want to inherit the prime minister's post from anyone.
The leader of the second-largest coalition party was commenting after Prime Minister Prayut Chan-o-cha said earlier last week that 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 said: "For me, I have to win the trust of the people first, as opposed to waiting [to be appointed a successor]."
At the upcoming gathering some 37 MPs who have decided to join the party will pledge their allegiance to Bhumjaithai, according to a source.
Bhumjaithai Party officials last week contacted Palang Pracharath Party (PPRP) MPs who want to defect to send over copies of ID cards so the party could arrange the party switching process.
Several PPRP MPs want to postpone their defection to late January because there is still time until the 90-day membership requirement. Under the election law, election candidates must have joined their party at least 90 days before voting day.
As MPs, it is easier for them to reach out to the constituents and woo votes, so some MPs may seek talks with Bhumjaithai key figures to delay their resignation, the source said.
Feb 7 is the last day of switching party if the House of Representatives completes its term on March 23. The Election Commission has announced a May 7 election if that is the case.
Those who remain undecided will also be there to observe the atmosphere before making a decision. These include some PPRP MPs who have been approached to follow Gen Prayut to the newly-established United Thai Nation Party (UTN).
Bhumjaithai is said to be urging potential defectors to hurry because it is deciding who to field at the poll. More defections are also expected in January when parties are close to making final preparations for the polls, the source added.
Paisal Puchmongkol, former adviser to PPRP leader Prawit Wongsuwon, wrote on Facebook that Gen Prayut's remark about "political heirs" is being treated as a joke among politicians. He said that by the time Gen Prayut leaves office in 2025, the military-appointed senate will have completed its five-year term and the new one is not authorised to join the MPs in the prime minister vote. The prime ministerial post is therefore for any party with the largest support to claim, he said.
"That's why parties don't accept the splitting of the four-year term proposal under which Gen Prayut takes the first two years. Those who do, can't face their supporters. So Gen Prayut's chance of returning to Government House is narrowing," he wrote.
He also said mass defections by the MPs may trigger a House dissolution. When changing party, MPs must resign and will lose their MP status. However, by-elections just a few months before the House's term concludes are not practical, so that may prompt the prime minister to dissolve the House to spare by-election expenses. On Saturday, House Speaker Chuan Leekpai warned that a House dissolution could not be ruled out despite the few months remaining until March 23.