In Thailand's wealthy capital, embattled Prime Minister Yingluck Shinawatra rarely ventures out in public because of fears for her safety. But in much of the vast rural northeast, her billionaire family are heroes.

The stark contrast reflects a deep political split between the government's northern strongholds and opposition heartlands where anti-government protesters are threatening to block polling stations on Sunday to prevent Yingluck's re-election.

Voters in the northeastern region of Isaan, home to a third of the population, have propelled three successive Shinawatra-backed governments to office -- the first in 2001 led by Yingluck's elder brother Thaksin.

In the sleepy, sun-baked village of Baan Dong Yaang in Udon Thani province, villagers say their loyalty to Thaksin is just reward for the cash and care he has lavished on Thailand's poorest region.

Residents rattle through a list of Thaksin's good deeds that have transformed their fortunes, including rice farming subsidies, universal healthcare, job-generating micro-loans and university scholarships for the poor.

"Before Thaksin, no politicians came here," said 47-year-old Somsamai Paporn, showing off her array of red T-shirts dedicated to the Shinawatra siblings.

"Thaksin understood our situation and helped us. Now we want to help him."

Thaksin, a controversial tycoon-turned-politician, was ousted in a military coup in 2006 and lives overseas to avoid jail for a corruption conviction he says was politically motivated.

His sister Yingluck's Puea Thai party swept to power in 2011 on a wave of support among the ousted leader's "Red Shirts" supporters. Her critics accuse her of being a puppet for her brother.

Somsamai said insults by protest leaders in Bangkok have tightened the bond between Thailand's poorest people and its most prominent political outcast.

"They say Isaan people are stupid and lazy. But we are the bones of the country. We grow the rice they eat in Bangkok. We build those beautiful buildings they live in," she said with tears in her eyes.

"It is painful that they hate us. But don't worry -- now we hate them too."

Somsamai said her family eked out a living until receiving a $300 micro-loan in 2006, courtesy of a fund established in every village by Thaksin.

It enabled her to expand her general store, build a bigger house and begin saving for the first time.

She has also benefited from a landmark "30 baht" (one dollar) scheme bringing access to healthcare to all.

Such policies, dubbed "Thaksinomics", have boosted the fortunes of many in Thailand's long-neglected north and northeast.

New family mansions, gleaming shopping malls and car showrooms reflect the wealth that has poured in over the past decade, although poverty remains stubbornly high in some areas.

Between 2001 and 2011, Isaan's Gross Domestic Product per capita more than doubled to $1,475, according to official statistics.

Over the same period, GDP in the Bangkok area soared from $7,900 to nearly $13,000.

But to the anti-government opponents in the capital, Thaksinomics has poisoned the kingdom.

His critics say the former telecoms magnate has siphoned off taxpayers' cash to buy the loyalty of an uneducated and easily manipulated voter bloc.

They accuse Thaksin of orchestrating an assault on the Thai social order, which is headed by the nation's revered but elderly king and supported by the Bangkok-based establishment.

A rice subsidy scheme has also become a lightning rod for anger among anti-government protesters who say it engendered widespread graft, punched a hole in the Thai public finances and knocked the kingdom from its position as the world's top rice exporter.

Even in Isaan some farmers now grumble about late payments for rice delivery, but so far there are few signs of a mass defection from the Shinawatras

Analysts warn the political divide may be pushing Thailand to the edge of a precipice.

Protesters, who want Yingluck to step down to make way for an unelected "people's council" to oversee reforms, have occupied key government buildings and forced Yingluck to work from undisclosed locations around the capital.

Ten people have died and dozens more have been wounded in clashes, grenade attacks and drive-by shootings in political violence in recent weeks.

The deep split "could lead to a violent but low-intensity civil war," warned Paul Chambers, director of research at the Institute of South East Asian Affairs at Chiang Mai University in northern Thailand.

In 2010, scores died in an army crackdown in central Bangkok on a Red Shirt rally against the previous government, which came to power by parliamentary vote after the courts ousted Thaksin's allies.

Anger is again building in the Red Shirts' heartland of Udon Thani, where radio host Kwanchai Pripana, a leading figure behind the 2010 rallies, was shot in the arm and leg when his house was sprayed with bullets by unknown gunmen last week.

Speaking to AFP from his hospital bed, where he is under 24-hour armed guard, Kwanchai predicted Puea Thai would sweep to victory on Sunday.

And he warned that the Red Shirts would refuse to accept the result being overturned by Thailand's notoriously interventionist courts.

"We will come out and obstruct, with the people's forces, just like we did in 2010. We fought against the tanks of the soldiers, we will fight," he said. "This time we will not surrender."