A long-awaited verdict in the trial of former Thai prime minister Yingluck Shinawatra this week could inflame tension and would likely have far-reaching implications in the politically divided kingdom.
The ruling military said more than 3,000 of Yingluck's supporters could show up at the court on Friday in what would be one of the biggest political gatherings since Yingluck's government was ousted in a 2014 coup.
Thousands of policemen will be on hand in a bid to head off the sort of trouble that has become a hallmark of antagonistic Thai politics over the past decade or more.
Yingluck has been accused of negligence in her handling of a multi-billion dollar rice subsidy scheme, under which the government bought rice from farmers at inflated prices.
That led to stockpiles of rotting grain, distorted world prices and lost Thailand its crown as the world's top exporter. Losses amounted to $8 billion, this government says.
Critics said the scheme was engineered by Yingluck's brother, former prime minister Thaksin Shinawatra, to shore up support among rural voters who have handed electoral victory to a Shinawatra party in every election since 2001.
Yingluck has denied wrongdoing and has said she is the victim of political persecution. She faces up to 10 years in jail if found guilty of negligence.
A military-backed legislature found her guilty in a separate impeachment case in 2015, and banned her from politics for five years, for failing to exercise sufficient oversight of the subsidy scheme.
Despite that, Yingluck remains the unofficial face of the Shinawatra political machine, which, supporters say, the royalist-military establishment is determined to sideline once and for all.
Opposition activists said a guilty verdict would fuel anti-government anger and could spark a smattering of small protests in defiance of a government ban, particularly in the north and northeast where support for the Shinawatras appears unwavering.
"If she is found guilty there will surely be some action by underground resistance forces," said a leader of the pro-Shinawatra "red shirt" movement in the northeastern city of Khon Kaen who declined to be identified.
"There are plans to burn tyres at up to 10 locations in Khon Kaen."
A spokeswoman said Yingluck did not agree with the threat by the activist leader to use force, and her party said any support for her should be peaceful.
Yingluck was at her Bangkok home on Wednesday, where she donated alms to Buddhist monks, and was preparing for the court's decision, her lawyer said.
"The defense team and former prime minister Yingluck are ready to hear the verdict," her lawyer, Norrawit Larlaeng, Yingluck's lawyer, told Reuters.
Police were setting up a barricades and a checkpoint outside the Supreme Court, where the verdict will be delivered, while Prime Minister Prayuth Chan-ocha, said the government wanted to avoid trouble.
"The government is worried about the people. We don't want to use force," Prayuth, a former army chief who ousted Yingluck's government in the 2014 coup, told reporters.
Former telecommunications tycoon Thaksin Shinawatra, overthrown in a 2006 coup and living quietly in self-exile to avoid a 2008 conviction for graft he said was politically motivated, has made no public comment on his sister's case.
Trakool Meechai, a former political science professor at Bangkok's Chulalongkorn University, said widespread sustained protests in response to a conviction of Yingluck were unlikely, given the firm grip the military has imposed.
But in the long-term, a conviction could deter future governments from intervening to support markets.
"No matter how this case turns out it will have an impact on Thai politics," Trakool told Reuters. "This case will be a litmus test for how future politicians will manage the country."
A verdict of innocent would invigorate the rank and file of the Shinawatras' embattled Puea Thai Party and boost its prospects in a general election the junta has promised to hold in 2018.
"If the case is thrown out it will increase the strength of Yingluck and her Puea Thai Party and this will show in the next election," Trakool said.
Two potential leaders have emerged to lead the party in the election, one of them from within the Shinawatra family.
But a guilty verdict would spell the end of Yingluck's political career, deal a heavy blow to the Shinawatras and their loyalists, and deepen the political divisions that the military has vowed to heal.