In an escalation of the government campaign to crush the beleaguered China Democracy Party, Chinese authorities sentenced a grass-roots organizer of the banned opposition group to 13 years in prison today for "subverting state power."

Liu Xianbin, 31, of central China's Sichuan province, was the fourth member of the China Democracy Party hit with a stiff jail term this week. His sentence was the heaviest meted out to a democracy campaigner since Dec. 21, when veteran dissident and party co-founder Xu Wenli was sentenced to 13 years--a term viewed as a warning to lower-profile activists.

China's ruling Communist Party allows no organized opposition, and it launched its first effort to suppress the China Democracy Party last November. The government sentenced three members, including Xu, to jail terms of more than 11 years and detained and jailed dozens of others. It later closed several liberal publications and tightened political controls, but the pace of the arrests slowed.

The latest round of arrests began in early May. Since then, more than 200 dissidents have been detained and 35 remain in custody, according to Lu Siqing, director of the Hong Kong-based Information Center of Human Rights and Democratic Movement in China. Nine have been sentenced to long jail terms, and Lu said he expects at least 15 more to be sentenced this month.

Lu said the Chinese government is using NATO's accidental bombing of the Chinese Embassy in Belgrade on May 7 as cover for its effort to "pull out the roots" of China's democracy movement in its harshest crackdown on dissidents in four years.

"The U.S. has been trying to repair Sino-U.S. relations, so even though China has cracked down on dissidents and is violating human rights, the United States hasn't come out with a strong condemnation," said Lu. "Communist Party leaders are using this period of lessened international pressure to convict dissidents."

Lu added that infighting among exiled Chinese dissidents has also prevented any strong, coordinated response to the crackdown.

Liu Xianbin was considered part of the second rung of the opposition party's leadership. Liu had helped establish its Sichuan branch last year and traveled to at least three provinces in January to promote the effort, despite the government's crackdown.

Liu also wrote open letters to President Jiang Zemin and Premier Zhu Rongji calling for release of Xu and the group's other jailed leaders. Prosecutors used those letters as evidence against him today during the trial, according to Liu's wife, Chen Mingxian, who sat in the gallery of the Suining Intermediate People's Court.

Curiously, Liu's hometown of Suining is the city that organized China's first direct township election last December. The vote in Buyun township, which is administered by Suining, was considered a breakthrough in efforts to democratize the countryside. But Chinese authorities distinguish between such reforms and the activities of dissidents, and Liu was treated harshly.

To protest what he considered unfair proceedings, Liu refused to answer questions from the prosecutors. His only defense came during the five minutes he was allotted for a closing argument, according to his wife.

The other opposition party organizers sentenced this week were She Wanbao, Zha Jianguo and Gao Hongming. They were given jail terms of 12, 9 and 8 years respectively.