Back in 2001 China's Olympic bid committee argued that awarding the 2008 Games to Beijing would “help the development of human rights”. The message was intended for foreign, not Chinese ears, but it has spread through more than a million Chinese chat rooms and 20 million blogs. Not only intellectuals, but elder statesmen within the Communist Party and even groups of semi-literate farmers are seizing their chance to air their grievances in a year when China's treatment of its citizens will be under scrutiny as never before.

China intended the Olympics to be the $40 billion showcase for its triumphant economic revival, but, as Beijing grooms half a million “volunteers” to take visitors helpfully in hand, the authorities are nervously realising that, with more than 20,000 journalists expected in town, it will be harder than they expected to hide from view the tensions and gross inequalities resulting from its chaotic dash for growth, or the reality that the political system is badly out of step with a rapidly changing society.

Increasingly outspoken demands for cleaner air, cleaner politics and a fairer society that respects individual rights are welling up from below — and not only from below. The Deng-era reformer Li Rui, an elder statesman too eminent to be silenced, declared just before October's party congress that China's most bitterly resented problems, rampant official corruption and appalling disregard for the environment, would not be cured without a “self-revolution” to open up the system.

Most talk of “democratic socialist liberalisation” means little more than cleaning up the Communist Party's act, the better to consolidate its control. But even President Hu Jintao has felt compelled to talk the talk of “earnestly respecting and guaranteeing” the “rights and interests of all social groups”, to repackage the party as the guardian of democracy and, in a sop to the urban middle classes, to allow town-dwellers to own private property. Most dramatically, he has declared that class struggle is an “incorrect concept” that must give way to “a people-centred approach” that offers opportunity to all.

Ideologically, the leadership has ventured on to thin ice. Private property and communism do not mix; and class struggle is what justifies the dictatorship of the proletariat and the party's absolute monopoly of power. In response, the party has been openly challenged to make good on its words. One provincial government adviser, Wang Zhaojun, published an open letter last month denouncing the entire political system; and at Nanjing University a young professor named Guo Quan announced the formation of a “New Democracy Party” backed, he said, by ten million campaigners, to oppose the one-party dictatorship that he called the “root of all China's social problems”. Mr Guo was stripped of his professorship and police have raided his home; but remarkably, he has not been arrested.

More embarrassing still to Beijing — and more unexpected — is the emergence of what could become a mass land rights movement by China's most powerless people, its 750 million heavily exploited farmers. Since December 9, in four separate developments, some 120,000 farmers in different provinces have banded together to announce that they have the right to own “their” land and are taking it back.

In Heilongjiang in the northeast, 40,000 farmers from 72 villages published a statement that they have reclaimed and redistributed more than 100,000 hectares; near Tianjin 8,000 farmers have claimed back land they claim was illegally grabbed by local government officials; in Jiangsu, farmers followed suit a few days later and in Sha'anxi, 70,000 migrant farmers announced that they are dividing the land around 76 villages “to own it for ever”. In an open letter, their leaders wrote: “We reject the previous form of collective ownership. It cannot guarantee the farmers' permanent rights to the land... and cannot prevent illegal infringement by officials and thugs.”

China's new property rights law emphatically does not extend to farmland, which by law belongs to the State or to village collectives, with farmers restricted to rights of use under 30-year leases that are not recognised as collateral for loans. The expropriation of land by profiteering officials has been the subject of thousands of protests, many violent, across China, where more than a million cases of illegal land acquisition have been uncovered since 1999.

But never before have farmers challenged not just corrupt practice, but the principle of collective ownership. Most of their leaders have been arrested and their letters wiped from the internet, and the party has proclaimed that there will be no return to “feudal” private land ownership. However, millions of Chinese will identify with their grievances; and the farmers' stand will strengthen reformists within the party's higher echelons who recognise that land reform is badly needed.

These are small strokes on a vast canvas, but they help to explain why the party's leaders are obsessed by what Mao called “contradictions among the people”, why the party employs thousands of internet censors, and also why it is insisting that the cadres must clean up their act.

When the Games open on the auspicious “triple 8”, August 8, 2008, on parade will be the prosperous China of glass towers, expressways mysteriously clear of traffic jams — and ubiquitous police. What no one in China knows for sure is whether demonstrators will slip past the security dragnets, or what will happen if they do. What must have looked to China's rulers like a safe bet in 2001 looks less safe in the pollution-fouled dawn of 2008.

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