INSIZA, Zimbabwe The cornfields that once flourished here are just memories now. The surging rivers have become sandy grazing grounds where goats feed on withered grass.

In this village of parched earth and wilting crops, more than half of all families need emergency food aid to survive. It is here, amid the hungry and the vulnerable, that members of Zimbabwe's governing party stand accused of trying to crush their political rivals by denying them food.

The militants seized sacks of cornmeal and peas from a UN distribution site and gave them to their supporters, turning away others because they were followers of the opposition party. And in the days before a local election, the governing-party activists kept bags of food in polling stations, to make their message plain: Vote against the party of President Robert Mugabe and you will go hungry. The United Nations suspended its operations in Insiza in October, protesting "the misuse of its resources for political ends," and the government promised that it would not happen again. But the culprits, though known, have not been arrested. And, at a time when drought and land redistribution have left nearly half of Zimbabwe's population at risk of famine, incidents persist. It is difficult to determine their frequency; they seem to occur much more often in the distribution of government-bought food than international aid. But the willingness of at least some officials to deny food to the opposition shows how rapidly Zimbabwe has transformed itself from a promising democracy into an authoritarian state. Mugabe, 78, who once won praise for building one of Africa's most prosperous and educated nations, has after 22 years seen his popularity plummet. In a desperate bid to hold on to power, he has condoned the killings and arrests of scores of supporters of the opposition over the past three years. The withholding of food for political reasons might seem consistent with such tactics. But officials say the opposition has yet to prove that these problems are widespread. A senior official recently told Western diplomats that "lessons had been learnt from the unfortunate incidents" in Insiza. Despite such assurances, however, supporters of the opposition in the capital, Harare, and in other towns say officials still demand party cards at some government distribution sites to ensure that only Mugabe's supporters buy grain. Here in Insiza, some frightened people say they have already stopped supporting their party publicly, to ensure that they will get food when distribution resumes. Zimbabwe's catalog of recent changes under Mugabe includes curbs on political meetings and threats against judges and journalists who challenge the government. White farmers have been forced to give their land to blacks as part of a government effort to undo the legacy of British colonialism. But the farm seizures and rights violations have discouraged foreign investment, which has in turn worsened an inflationary economy. Yet of all Zimbabwe's problems, it is the politicization of food that has been ringing alarm bells in Western capitals recently, with strong statements of concern coming from the United Nations, Europe and the United States. Andrew Langa, the governing-party candidate who won the parliamentary election here in Insiza, says he understands why political interference happens during food distributions, although he denies using food to manipulate the voters. "No one should politicize aid; I'm quite clear about that," Langa said in an interview. "I represent everybody, all the citizens of Insiza, and I know they all need food. "But I also understand how our people feel," he said. Speaking of the leading opposition group, the Movement for Democratic Change, and its perceived colonialist ties, he asserted: "People see the MDC as a British-sponsored party. They're against land reform, so people regard them as an enemy. So if I have maize and you and one of my party supporters come to me, who do you think I would sell to first?" Supporters of the opposition, for their part, feel crippled by such attitudes. "My supporters don't come to me now, because they know I have nothing," said Mathilda Dube, a local opposition official. "They know we are not allowed food because we are MDC." So far, there are no signs of imminent starvation, no hollow faces or emaciated bodies among the people lining up for food. But malnutrition levels are rising, because many people subsist on one meal a day. Western diplomats say that in the distribution of relief aid - as opposed to government-bought food - incidents of political interference have been relatively infrequent.