Hong Kong's serried ranks of high-rises, stuffed with small flats, are the epitome of modern city living. Yet more than half of the 425 square-mile territory is green: outside the dense urban centers lie countryside and mountainous jungle dotted with ancient villages. Many are still inhabited by the clans who founded them hundreds of years ago.

Families gather in ancestral halls bearing the names of their forefathers, who are buried in traditional horseshoe-shaped graves nearby, nestled at the spots on the hillsides with the most auspicious feng shui. By dint of this historical connection, some villagers receive a valuable and controversial privilege: the right to buy land at a discount from the government and to build a house on it, of a size most Hong Kongers would envy.

The system has become a topic of fierce debate in the territory — a proxy war, in effect, between prodemocracy activists and the most powerful defender of the privileges: China's ruling Communist Party.

The party seized power in China 68 years ago on the back of a rural rebellion fueled by hatred of landlords. In Hong Kong, however, the twists and turns of history have left it on the other side; the territory's rural landowners are a pillar of the party's support.

They have a seat reserved for them in Hong Kong's quasi-parliament, the Legislative Council (or Legco). They also have 26 guaranteed seats in the 1,200-member committee that elects Hong Kong's leader. In a territory bitterly divided between democrats and the party's backers, the party needs any friends it can get.

In recent months, prodemocracy politicians have been mounting a vocal campaign against the rural landowners, whose privileges they consider deeply unfair. At issue is what is known, ironically enough, as the "small-house policy." This was introduced in 1972, a quarter-century before Britain handed Hong Kong back to China. It grants male villagers the right to build a house of up to three stories on a plot of land in their ancestral village. If they have no land themselves, they can buy it from the government at a discount.

It is a policy wrapped in layers of unfairness. First, there is the obvious discrimination between men and women: the policy is exempt from Hong Kong's sex-discrimination laws. It applies only to "indigenous" men who can trace their ancestry through the male line to occupants of their village at the time when Britain took control.

Therein lies a third layer of inequity: the policy applies only to inhabitants of villages in the New Territories, a largely rural district of Hong Kong. Villagers in the rest of Hong Kong (there are very few of them) do not get the same deal.

By Hong Kong's standards, the "small houses" are palatial. They typically have a floor area of 2,100 square feet. The most common type of apartment built by developers in recent years, in contrast, is the "micro-home," of 215 square feet or less. To many urban Hong Kongers, who struggle to buy even such minuscule dwellings in what is one of the most unaffordable cities in the world, the small-house policy seems grossly unjust. Worse, it is often abused by villagers who make fortunes by illegally selling their rights to developers or by selling their houses, which can go for millions of dollars.

Recipients argue that the scheme is less generous than most Hong Kongers suppose. As homes can only be built in areas designated by the government, many villagers own land they are not allowed to build on. And some villages are running out of land for construction. What is more, most villages are not connected to the sewage system; some have no water or roads. Applications to build a small house can take years to be approved, and if their owners want to sell within five years they must pay a penalty to the government.

Few outside the villages are sympathetic. The New Territories are now home to half of Hong Kong's 7 million people. Most live in small apartments in new towns; many live in illegally subdivided flats or wait years for public housing. One of the leaders of the campaign against the villagers' economic and political privileges is Eddie Chu, a prodemocracy legislator and founder of a group called the Land Justice League.

Chu accuses rural landowners of hiring thugs to intimidate unfriendly politicians and adversaries in land disputes and says the government is unwilling to do battle with the rural landowners.

But Chu is up against a powerful force: the Heung Yee Kuk, an advisory body to the government that holds considerable sway in rural politics. It is this body, usually known as the Kuk (meaning "council"), that represents the landowners in Legco and the election committee.

Junius Ho, a legislator and member of the Kuk, can trace his family back 32 generations. He agrees that the small-house policy is contentious, but only because "people have sour grapes."