The new leader of Thailand's pro-government "red shirt" movement said on Monday that his supporters would take to the streets in support of Prime Minister Yingluck Shinawatra if the elite or the courts dared try to oust her.
The red shirts have kept to the sidelines during the past 4-1/2 months of political unrest in Thailand, while anti-government protesters forced state offices to close and disrupted an election in February.
Any further threat to Yingluk could see their patience snap, warned Jatuporn Prompan, who became leader of the United Front for Democracy against Dictatorship (UDD), as the red shirts are formally known, at the weekend.
Thousands of supporters attended the rally in Ayutthaya north of Bangkok to witness the change of leadership.
"We're going to fight tooth and nail to defend this government but we will do so peacefully," Jatuporn told Reuters on Monday.
"Thailand's political crisis will not end with these street protests. This is about the Bangkok elite denying grassroots people the right to play a part in the democratic process. We can't let this go on."
The crisis pits protesters, mainly middle class Bangkok residents and southerners backed by the military and the establishment, against supporters of Yingluck and her brother, ousted former premier Thaksin Shinawatra, from the rural north and northeast.
If the red shirts were to launch counter protests it would risk escalating violence, and could further destabilise Yingluk's government. Their restraint, however, could disappear, under the new leader.
Jatuporn helped organise the uprising against a previous government that ended in a bloody military crackdown in May 2010, and supporters like his no-nonsense attitude.
He replaced Thida Thawornseth, a former member of the banned Communist Party of Thailand whose schoolteacher demeanour and lofty speeches left some wondering whether she was out of touch with the movement's grassroots supporters.
"Thida had the theories, but Jatuporn is a man of action. We can count on him to lead us," said Chinawoot Eak-pan, an office security guard and red shirt supporter from Bangkok.
Jatuporn still faces terrorism charges related to the violence in 2010.
On Monday, Thai army chief Prayuth Chan-ocha called Jatuporn "a bandit", telling reporters that "if they (red shirts) are aggressive towards the military, I'll be aggressive, too".
WARNING OF HAVOC
Weakened by the agitation against her, Yingluck faces a raft of legal challenges that could force her out, the most prominent being charges of negligence over a ruinous rice subsidy scheme.
Twenty-three people have been killed in politically related violence in Bangkok and eastern Thailand since late November.
On Monday, two home-made bombs were found and destroyed by bomb disposal teams outside the Office of the Attorney General in Bangkok, police said.
With the noose tightening around Yingluck's Puea Thai Party, many government supporters believe Jatuporn's skills as a fiery orator will rally the support her government needs to hold on.
Red shirt supporters say they are prepared to fight back if the government they helped put in office is removed.
Despite signs of a split in the movement, the red shirts remain a potent force and are largely loyal to Thaksin, seen by many as the real power in the country.
The protesters in Bangkok say they want to curb Thaksin's influence, remove Yingluck and install an unelected "People's Council" that would oversee wide-ranging political reforms to dilute their chances of winning election again.
Jatuporn has said he will avoid a confrontation with the demonstrators but some analysts say it could still happen.
"He's capable, if Thaksin told him to, of having the red shirts engage in violence," said Paul Chambers, director of research at the Institute of South East Asian Affairs in Chiang Mai. "There is a message that is being sent to the elite with Jatuporn's accession, which is: 'This is the person who really might create havoc for you'."