(Repeats from late Friday, no changes to text)
By Jason Szep and Amy Sawitta Lefevre
BANGKOK, Dec 13 (Reuters) - His whistle-tooting crowds of supporters are dwindling. His threats against Thai Prime Minister Yingluck Shinawatra veer from the bold to the bizarre.
But behind Thailand's fiery anti-government protest leader, Suthep Thaugsuban, are two powerful retired generals with palace connections, a deep rivalry with the Shinawatra family and an ability to influence Thailand's coup-prone armed forces.
The forces behind Suthep are led by former defence minister General Prawit Wongsuwan and former army chief General Anupong Paochinda, towering figures in Thailand's military establishment, said two military sources with direct knowledge of the matter and a third with connections to Thai generals.
A glimpse into Suthep's connections sheds light on how he could prevail in a seemingly improbable bid to oust a leader who won a 2011 election by a landslide and impose rule by an unelected "People's Council" of appointed "good people", even as his street rallies start to flag.
Although retired, Anupong, 64, and Prawit, 67, still wield influence in a powerful and highly politicised military that has played a pivotal role in a country that has seen 18 successful or attempted coups in the past 81 years.
It is unclear how far that influence goes, or how decisive they could be. But both have close ties to army chief General Prayuth Chan-ocha. And all three have a history of enmity with Yingluck's billionaire brother, former prime minister Thaksin Shinawatra, who they helped oust in a 2006 coup.
The military sources said that if Suthep's protests lead to violence, the two could help sway the military to intervene or even to seize power on the pretext of national security, allowing Suthep to go ahead with his People's Council, though analysts say such a scenario appears unlikely in the immediate term.
The two were not available to comment despite requests from Reuters.
Anupong and Prayuth served with the Queen's Guard, an elite unit with greater autonomy from the rest of military, with its allegiance foremost to the monarchy rather than the direct chain of command, said Paul Chambers, director of research at the Institute of South East Asian Affairs in Chiang Mai, Thailand.
While most Thais still express steadfast loyalty to 86-year-old King Bhumibol Adulyadej, his throne is seen as entwined with the political forces that removed Thaksin, especially ultra-nationalists who in the past have worn the king's colour of yellow at protests and now back Suthep.
As his reign gradually draws to a close, long-simmering business, political and military rivalries are rising to the surface, forcing Thailand to choose sides between supporters of the Bangkok establishment or those seeking to upend the status quo - a constituency associated with Thaksin.
Crown Prince Maha Vajiralongkorn has yet to command the same popular support as his father, raising questions over whether royal succession will go smoothly. The palace did not reply to requests for comment.
Prawit and Anupong had expressed readiness to intervene if there was a security crisis, such as a crackdown by police on protesters or clashes between pro and anti-government demonstrators, and if Suthep's plan for an interim government was constitutional, said the source with military connections.
Army leaders say they are neutral in the crisis. But Tanasak Patimapragorn, supreme commander of the armed forces, will meet on Saturday with Suthep and his allies, who have openly courted violence on Bangkok's streets in hopes of inducing a military coup or judicial intervention to bring down Yingluck.
Suthep says the meeting shows he has public backing of the military. But a statement from the supreme commander says the meeting is a "public forum" that includes civic groups.
On the face of it, Suthep's bid to upend Thailand's current political order looks far-fetched.
The former deputy prime minister has called for a parallel government and a volunteer police force. He wants Yingluck arrested for insurrection and has ordered civil servants and the army to report to him, not the government.
Struggling to defuse the crisis, Yingluck has set parliamentary elections for Feb. 2, which Suthep and his allies have ignored but which a pro-Shinawatra party is almost certain to win, as they have in every election since 2001.
The military has provided little security for her caretaker government at protests, such as on Thursday when demonstrators cut power to Government House, Yingluck's office, and scaled a wall to enter the compound.
The military has left police to control the crowds, unlike 2010 when a Democrat-led government was in power and the soldiers used force against pro-Thaksin protesters.
"That means a government that is not supported by the elite cannot enforce the law. Once a lot of violence takes place and the government cannot enforce the law, then this country becomes a failed state. Then there can be a pretext for the military to come in," said a senior member of Yingluck's Party.
The army denies it is taking sides.
"We try to avoid getting ourselves involved directly or be seen as taking sides," army spokesman Colonel Werachon Sukondhadhpatipak said, adding that the military is trying to encourage all sides to remain peaceful rather than conduct crowd control.
Asked if the military supported the government, he replied: "At the moment, yes."
"PLAYING THE GAME"
The impasse is a reminder of the turmoil that has overshadowed Thailand for much of the last decade.
On one side is Thaksin, a former telecommunications tycoon who redrew the political map by courting rural voters to win back-to-back elections in 2001 and 2005 and gain an unassailable mandate that he then used to advance the interests of major companies, including his own.
On the other are the elite and establishment, threatened by his rise. Thaksin's opponents include unions and academics who saw him as a corrupt rights abuser, and the urban middle-class who resented, as they saw it, their taxes being used as a political war chest for Thaksin, his sister and their allies.
Failure to quell the demonstrations makes her vulnerable to the same military and judicial forces that toppled two Thaksin-allied prime ministers in 2008, said Boonyakiat Karavekphan, a political analyst at Ramkamhaeng University in Bangkok.
"If Prawit and Anupong back Suthep, it could help sway the decision makers in the military to not side with the government which gives Suthep's movement more legitimacy," he said.
"No matter how you look at it, the military is an important pressure group in Thai politics," he said. "The people's movement has come as far as it can on its own. It now needs a push from other quarters."
Anupong was a leader of the military coup that removed Thaksin in September 2006 and two years later recommended on television that the Thaksin-allied prime minister step down. As army chief, he oversaw a bloody crackdown on Thaksin's red-shirted supporters in 2010 in which 91 people, mostly red shirts, were killed. Anupong made Prayuth his heir apparent.
A former army commander, Prawit was a mentor of Anupong and a defence minister under the previous government replaced by Yingluck in the 2011 election. He's also a close associate of former general Sonthi Boonyaratkalin, leader of the coup against Thaksin, who now lives in self-exile to avoid jail for corruption, a charge he says was politically motivated.
"Suthep is playing the game on the outside while Prawit tries to play the game on the inside," said a senior military official who could not be identified because he was not authorised to speak to the media. "General Prawit has been clear about his aspirations to become prime minister."
Anupong and Prawit were present at a Dec. 1 meeting between Suthep and Yingluck at a military camp, according to three aides of military officials who attended.
One military source said Prayuth was being pulled in two directions, with Anupong and Prawit on one side, and a need on the other to restore the military's image after the 2010 clashes and ensure an untarnished retirement in 2014. (Additional reporting by Martin Petty; Editing by Nick Macfie)