The pro-government United Front for Democracy against Dictatorship (UDD) will hold a mass rally in Bangkok one day before the Constitutional Court rules on caretaker Prime Minister Yingluck Shinawatra's status.
The UDD says the rally may last for several months. Red-shirt supporters would be told closer to the date when the court is likely to deliver its ruling, but many observers expect the court will rule on Ms Yingluck's status by the end of the month.
Tens of thousands of red shirts attended a rally earlier this month in the Buddhamonthon area of eastern Bangkok, held mainly to show support for Prime Minister Yingluck Shinawatra. (Photo by Pattarachai Prechapanich)
The case relates to her transfer order for Thawil Pliensri, secretary-general of the National Security Council. The Supreme Administrative Court has already ruled the transfer was unlawful.
Based on the Supreme Administrative Court's ruling, many believe the Constitutional Court will also rule against Ms Yingluck, which could destabilise the status of the entire government.
Some believe the ruling will single out the cabinet members who were involved in approving the transfer order, which could leave Ms Yingluck without vital members of her team. Debate has also started about who would be in a position to appoint an interim premier, should one be needed.
Tida Thawornseth, UDD advisory group chairwoman, said red-shirt supporters nationwide have been asked to prepare for the mass gathering.
"This time, we ask for the biggest ever gathering to prove our rally is much bigger than that of the PDRC [People's Democratic Reform Committee] anti-government protest group," she said.
"Our next gathering will determine the future of the country and ensure there will be no more like him [PDRC secretary general Suthep Thaugsuban]," she said.
Ms Tida said the UDD would not allow Mr Suthep or his group to take sovereign power from the people. UDD chairman Jatuporn Prompan added that the UDD would fight to win.
"I'm challenging Mr Suthep to prove whose gathering is the biggest, and I'm calling on the Democrat Party to make clear whether it will field candidates in the next election," he said.
Weng Tochirakarn, UDD co-leader, said the rally might last for two or three months, so supporters must prepare themselves.
Charnyuth Hengtrakul, UDD leader in the eastern region, said if the court rules to end Ms Yingluck's status, red shirts from all regions will encircle the capital and topple the amart (old elite).
Meanwhile, the PDRC says it is confident the court will help deliver it a victory in its campaign to topple the government. Mr Suthep has called on PDRC supporters to prepare for a mass rally after Songkran. He said the gathering could last several days.
Nataphol Teepsuwan, a PDRC leader, told protesters at Lumpini Park he had found places to host victory celebrations for the PDRC, such as the Democracy Monument on Ratchadamnoen Klang Avenue.
Uthai Yodmanee, a Network of Students and People for the Reform of Thailand (NSPRT) leader, said the NSPRT would boost its rally tomorrow.
“Our actions will intensify to bring us to victory quickly. We expect the [battle] will end this month,” said Mr Uthai.
The NSPRT will also visit government offices to call on employees to join the anti-government movement, similar to the recent campaign by the PDRC.
NSPRT will run its own anti-government rally in collaboration with PDRC, he said.