Imprisoned dissident Wang Bingzhang is on the brink of a nervous breakdown due to the 'mental torture' he has suffered in jail, and is threatening to go on a hunger strike, his brother says. Wang Bingwu, who visited his older brother at a prison in Shaoguan, Guangdong, last Friday, said he found the solitary confinement and mandatory 'political education' imposed three times a day increasingly difficult to bear. 'He told me to tell the world that in order to end his solitary confinement and mental torture, he would go on a hunger strike,' Mr Wang said in Hong Kong yesterday. Critics say the so-called 'political education' sessions in mainland prisons typically include several hours of brainwashing, forced self-criticism and confession of alleged crimes. Bingzhang, 55, is a permanent resident of the United States. He went to Vietnam in June last year, where he was reportedly kidnapped and taken to Guangxi province. He was arrested and convicted on espionage and terrorism charges and given a life sentence in February. He was found guilty of providing intelligence to Taiwan between 1982 and 1990. He and his family deny the charges. Mr Wang said his brother looked frail and was suffering from stomach ailments and varicose ulcers. He said his brother was given medicine in prison but was banned from taking other medication that his family brought from America. Originally trained as a medical doctor, Bingzhang is a Christian and is known for his view that people have the right to overthrow their government in a revolution.