By Amy Sawitta Lefevre
BANGKOK, Dec 12 (Reuters) - Anti-government protesters in Thailand pinned their hopes on winning support from the powerful security forces on Thursday to take forward a campaign to oust Prime Minister Yingluck Shinawatra and install an unelected administration.
Protest leader Suthep Thaugsuban, a firebrand veteran politician, has asked police and military chiefs to meet him by Thursday evening and choose their side in the latest crisis engulfing Southeast Asia's second-biggest economy.
The politically powerful army has staged or attempted 18 coups in the past 80 years - including the ousting of Yingluck's brother, Thaksin Shinawatra, in 2006 - but it has said it does not want to get involved this time, although it may mediate.
The latest crisis in an eight-year, on and off, political conflict again centres on Thaksin, with protesters viewing Yingluck as her brother's puppet. Thaksin lives in self-imposed exile. He was convicted in absentia of graft in 2008 but he dismissed the charges as politically motivated.
Thaksin, a former telecommunications tycoon, courted rural voters to win back-to-back elections in 2001 and 2005 and gain an unassailable mandate that he used to advance the interests of major companies, including his own.
His opponents are Thailand's royalist elite and establishment who feel threatened by his rise. Trade unions and academics see him as a corrupt rights abuser, and the urban middle-class resent, as they see it, their taxes being used as his political war chest.
Yingluck was forced on Monday to call an early election for Feb. 2, as 160,000 protesters massed around her office. But the protesters have rejected the ballot.
They want an unelected "people's council" to run the country and say Yingluck and her ministers should step down now. She is caretaker prime minister until the election.
"If a plane crashed with the whole cabinet in it and they all died, Thailand would still go on," protest leader Suthep told supporters late on Wednesday.
Thaksin's supporters have said they would weigh in to defend Yingluck if Suthep seemed poised to overthrow her. On Wednesday, pro-Thaksin leader Jatuporn Promphan promised to mobilise crowds that dwarfed the recent anti-government protests.
Thaksin's "red shirt" supporters brought central Bangkok to a halt for weeks in April and May 2010 in protests aimed at forcing then Prime Minister Abhisit Vejjajiva to call early elections.
That protest was put down by the military. More than 90 people, mostly Thaksin supporters, died over the two months.
Abhisit and Suthep, who was a deputy prime minister in Abhisit's government, have been charged with murder related to those events. Suthep was in charge of a crisis control centre that authorised "live fire" zones.
Formal proceedings start on Thursday and both men have been summoned to the criminal court. Suthep has said he won't go.
Suthep's campaign to oust Yingluck has been strong on rhetoric but failed to stop the government from functioning.
Missed deadlines for Yingluck to resign have become the norm for a protest movement that has openly courted anarchy on Bangkok streets in the hope of inducing a military coup or judicial intervention that, as in the past, might disband Thaksin-allied parties or ban their leaders from politics.
Suthep's statements have been bewildering at times. He has told police to arrest Yingluck for treason, ordered civil servants and security forces to report to him and not the government, and has called for citizen "peacekeeping forces" to take over from police. (Writing by Martin Petty and Alan Raybould; Editing by Michael Perry)