The embattled Thai government's hardline "red-shirt" supporters in the country's north say they are ready to resist any attempt by the military to stage a coup.
Some supporters say they also expect popularly elected Prime Minister Yingluck Shinawatra to retreat to Chiang Mai and set up government there if the army tries to take power in Bangkok amid ongoing anti-government demonstrations.
While some experts consider the government relocating an unlikely prospect, supporters like red-shirt activist Mahawang Kawang say their movement is large enough to challenge the military.
"We have no fear. All red groups will unite. We are willing to sacrifice our lives," said Kawang, who is president of the alumni association of Yupparaj school in Chiang Mai where Yingluck was once a student.
"It is likely the government will move to Chiang Mai. We can defeat tanks because we have the numbers," Kawang added.
Yingluck and her ruling Puea Thai party won the last election in 2011 in a landslide, thanks largely to support in the country's north, a stronghold for her brother, former premier Thaksin Shinawatra. Another election has been called for Sunday, but "yellow-shirt" protesters opposed to Yingluck and her tycoon brother have vowed to disrupt it and overthrow the government.
The yellow-shirts draw their main support from Bangkok's middle classes, the country's royalist elite and factions of the military. Thaksin's rural supporters have helped him and his allies win every election since he appeared on the Thai political scene in 2001.
Thaksin was forced from power in a 2006 coup and went into exile. Corruption convictions prevent his return to Thailand. Although the army has vowed to stay out of the current red-yellow turmoil, Yingluck's supporters eye the generals warily.
Ever since a 2010 crackdown on the red-shirts in Bangkok, thousands of villages in northern and northeast Thailand have been flying red flags.
The election is going ahead despite the anti-Thaksin movement's campaign to disrupt polling.
Government supporter Pichit Tamoon, who is Chiang Mai general secretary for the United Front for Democracy against Dictatorship (UDD), said: "We have police forces on our side and together with the northeast we have the backing of 37 [out of 77] provinces. Yingluck will win."
Red-shirt organiser Supon Fumuljaroen, a former classmate of Thaksin, is now vice-chairman of the UDD in Chiang Mai province. They both hail from the small town of San Kamphaeng, about 30 minutes' drive from the city of Chiang Mai.
Supon, a former policeman, said: "The majority of red-shirts really like the idea of a separate state. If they stage a coup, we can live without Bangkok."
Pinkaew Laungaramsri, a sociologist at Chiang Mai University, said the north-south divide meant that Thailand was breaking up.
But while some in the red-shirt camp envision the government setting up camp in Chiang Mai, not all observers think such an outcome is sustainable. Pavin Chachavalpongpun, a Southeast Asia analyst at Kyoto University, said that a breakaway state was possible but that without international recognition it was unlikely.
Ten people have been killed since the protests began in November. In a sign tension was escalating, an anti-government protest leader was shot and killed in Bangkok on Sunday as demonstrators blocked polling stations set up for early voting.
Last Wednesday, Kwanchai Praipana, a leader of the red-shirt movement, was seriously injured after an unidentified gunman opened fire as he sat reading a newspaper on his front porch. Just a day earlier, he had warned that a nationwide "fight" would ensue if the military staged another coup.
A recent report in the Bangkok Post cited red-shirts saying that their underground networks had stockpiled weapons and that they were familiar with the use of arms. But when red-shirts were asked by the South China Morning Post whether they had access to weapons, they gave mixed responses.
Kamsai Audomsi, UDD chief for San Khamphaeng and a roasted banana vendor, said: "We can't say what we are preparing and stockpiling. We cannot speak about arms or whether we have them or not."
UDD organiser Tamoon said: "We have no arms but we have the police force on our side."
If there is a coup, there is a general expectation among the UDD that some middle-ranking officers based in the north will refuse to follow orders.
Additional reporting by Reuters