Questions have been raised whether Sunday's planned gathering of political activists led by red-shirt leader Jatuporn Prompan will gain any momentum after other core red-shirt leaders decided not to join the event.
Mr Jatuporn, who created confusion among red-shirt supporters regarding his political stance, has launched a fresh movement on behalf of the "Thai Mai Thon (Impatient Thais)" group to topple Prime Minister Prayut Chan-o-cha.
The main activist group that has accepted Mr Jatuporn's invitation to join his new movement and today's gathering is the "Samakkhi Prachachon", or Uniting People group. It is the brainchild of a support group for relatives of the victims of the Black May protest in 1992.
However, the movement's launch met with a cold response from other core red-shirt leaders, including Nattawut Saikuar, a red-shirt leader who stood shoulder-to-shoulder with Mr Jatuporn during the United Front for Democracy against Dictatorship (UDD) rally against the Abhisit Vejjajiva government in 2010.
Mr Nattawut said he had no plans to reunite with Mr Jatuporn and the issue had never come up during their talks.
Mr Nattawut has just completed a jail sentence of two years and eight months for leading a violent red-shirt protest more than a decade ago outside the residence of the late Privy Council president Prem Tinsulanonda.
He and other red-shirt leaders, including Tida Tawornseth, Weng Tojirakarn and Korkaew Pikulthong, held a press conference on Tuesday and announced their support for the student-led movements, a stance that contradicts that of Mr Jatuporn.
Mr Jatuporn previously warned student activists to refrain from mentioning the monarchy or else they will face a public backlash.
In response, Mr Jatuporn said on Facebook Live on Friday that he will step down from his position as UDD chairman and hand it over to Mr Natthawut if the latter joins the student rally.
Mr Korkaew said he doubts Mr Jatuporn will be able to rally enough support from the youth-led demonstrators and red-shirt supporters, adding Mr Jatuporn may have alienated them.
A source in the opposition Pheu Thai Party said Mr Jatuporn wants to restore confidence and credibility in himself after having alienated his allies while expressing scepticism that the movement will get off the ground.
The source said no potential ally has responded to Mr Jatuporn's call.
"The alliance could be formed temporarily if they can find mutual benefits," the source said. "But [Mr Jatuporn's] power has dwindled so much."
Call for the May 1992 spirit
Although Sunday's event will be organised under the format of a seminar and speeches with no plan to march, it will offer a glimpse into whether Mr Jatuporn's new campaign will gather momentum.
The campaign is being closely watched because it is expected to draw in people who took part in the May 1992 popular uprising against the Suchinda Kraprayoon administration.
Despite differing political affiliations, many of those who took part have remained close, especially after the May 2014 coup. Several of their social gatherings are said to be coordinated by Adul Khiewboriboon, leader of the Samakkhi Prachachon group.
Mr Adul initiated Sunday's planned event and decided to model it after the May 1992 uprising.
"We made our call in May last year for Gen Prayut to step down and let the country move forward," he said. "[The PM] didn't respond and didn't keep promises."
"This time I'm asking Thais and those who joined the 1992 May uprising to step out and tell Gen Prayut to give up his power."
The Covid-19 outbreak linked to gambling dens and illegal border crossings by migrant workers indicate that Gen Prayut has allowed corrupt practices under his watch and the premier has also used the pandemic to suppress dissidents, Mr Adul said.
He said his group does not advocate the use of violence and insisted he will not urge its supporters to take it to the streets.
Mr Adul said the group will not involve the royal institution in its movement. He said the next move will be decided after today's event.
"The movement isn't spearheaded by Mr Jatuporn. It's my call. I believe that our ties from the May 1992 event are above red shirts or yellow shirts," Mr Adul said.
Campaign targets PM
Mr Jatuporn said he started mounting the campaign after it was agreed that Gen Prayut is the source of the problems and he should be removed from power by the means of a popular uprising similar to the May 1992 event.
"We came to a conclusion that as people live among conflicts, Gen Prayut will stay on for at least six years and we have no chance with the charter rewrite [demand]," he said.
The prime minister has two years in office and the support of the military-appointed Senate with a six-year term.
The Senate has the power to join in a vote to elect a prime minister, and Gen Prayut has a strong chance of returning to power when the next general election comes around.
Mr Jatuporn said he believes political activists from various affiliations can patch up their differences and reunite for his new fight.
He said the activities today will be limited to Santiporn Park and will focus on creating a common understanding about the political situation in the kingdom. He said the group will avoid a confrontation at all costs. He did not comment on the apparent lack of support for his campaign.
Pibhop Dhongchai, former yellow-shirt leader of the People's Alliance for Democracy, said he has agreed to join the activities as an individual.
"We have to exert pressure on Gen Prayut, who has support from the ruling Palang Pracharath Party and the Senate so they will vote for the referendum law."