BEIJING (AP) _ Chinese dissidents released a letter to the nation's leaders on Saturday, urging them to make good on promises to respect human rights and release democracy advocates jailed in a recent crackdown.

The letter signed by 184 dissidents throughout China focused on the case of Wang Youcai, a student leader in the 1989 democracy demonstrations who is expected to go on trial soon for trying to set up an opposition political party.

Xu Wenli and Qin Yongmin, veteran dissidents also active in leading efforts to found the China Democracy Party, were seized on Nov. 30 and have been accused of endangering state security. Wang was already in custody when police raided the homes of Xu and Qin and took them away.

The letter, released by New York-based Human Rights in China, urged President Jiang Zemin and Premier Zhu Rongji to release the three and other democracy advocates who have been seized in recent months.

It also urged them to halt Wang's upcoming trial and, failing that, to ensure it is open, fair and held in a court that is not under the direct control of the government or ruling communist party.

In the letter, the dissidents argued that China has made progress in protecting citizens' rights and applauded China's recent signing of two key human rights treaties. But it warned the arrests were a setback that produced ``doubts and deep disappointment.''

Among those signing the letter were Xu Liangying, a scientist who has written articles urging democratic reform, and Ding Zilin and Jiang Peikun, who have tried to seek redress for the killing of their 17-year-old son and other victims of the army attack on unarmed pro-democracy protesters in Tiananmen Square in 1989.

Meanwhile, the Information Center of Human Rights and Democratic Movement in China reported Saturday that Wang was having trouble finding a lawyer willing to take his case.

Wang Wenjiang, a lawyer from Liaoning province who agreed to take the case, was detained by police Friday and released Saturday after police warned him to stay away from the case, the Hong Kong-based center said, adding that the lawyer was no longer planning to handle the defense.

Under pressure from officials, another lawyer whom Wang's wife, Hu Jiangxia, tried to hire refused to represent Wang unless he pleaded guilty, the Information Center said. The court also refused to allow a friend of Wang's to defend him, it said.

Despite the crackdown on key figures trying to set up the opposition party, authorities have not closed off all avenues of discussion of human rights. Before a gathering of about 15 people in a small office on Saturday, Ren Wanding, a fellow activist with Xu and Qin in the Democracy Wall movement of the late 1970s, gave a speech commemorating the 50th anniversary of the Universal Declaration of Human Rights.