(CNN) — Just days before his father faces court in what's being billed as China's trial of the century, the son of former high-flying politician Bo Xilai has expressed hope that his father is able to "defend himself without constraints."
In a statement supplied to the New York Times on Monday, Bo Guagua writes that it's been 18 months since he's been in contact with his father or mother, Gu Kailai, who is serving a suspended death sentence.
"I can only surmise the conditions of their clandestine detention and the adversity they each endure in solitude," he wrote.
Gu was found guilty in August of the 2011 murder of British businessman Neil Heywood in a Chongqing hotel room. A family employee, Zhang Xiaojun, was also convicted in the killing and sentenced to nine years in prison.
The elder Bo is due to face trial on Thursday charged with bribery, corruption and abuse of power.
"I hope that in my father's upcoming trial, he is granted the opportunity to answer his critics and defend himself without constraints of any kind," the younger Bo wrote.
However, he adds: "If my well-being has been bartered for my father's acquiescence or my mother's further cooperation, then the verdict will clearly carry no moral weight."
During her one-day trial, Gu issued a statement saying she didn't deny allegations that she poisoned Heywood, but she said she did so because she thought her son's life was in danger, according to the state-run Xinhua news agency.
Bo: Mother 'silenced'
Bo wrote Monday that his mother had been "silenced" by the sentence, and was unable to defend herself against the "opportunistic detractors that attack her reputation with impunity."
"She has already overcome unimaginable tribulation after the sudden collapse of her physical health in 2006 and subsequent seclusion," he wrote.
"Although it is of little comfort to my anxiety about her state of health, I know that she will continue to absorb all that she is accused of with dignity and quiet magnanimity."
Before March 2012, the Bo family was considered part of China's political elite.
The elder Bo was chief of the bustling metropolis of Chongqing, in the country's southwest. His wife, Gu, a high-flying lawyer, and their son were the beneficiaries of his family's wealth and connections at the top of Chinese politics.
However, their privileged position started unraveling in March 2012, when Bo's right-hand man, then-Chongqing police chief, Wang Lijun, fled to the U.S. consulate in Chengdu with claims that Gu had been involved in Heywood's murder.
Bo was subsequently stripped of his posts and disappeared from public view.
In one of his final statements, Bo condemned the treatment of his family, branding personal attacks as "sheer rubbish."
"A few people have been pouring filth on Chongqing and me and my family," Bo said. "They even say that my son studies abroad and drives a red Ferrari. Sheer rubbish! I feel really furious. Sheer rubbish!"
In the weeks after the allegations emerged, photos of Bo Guagua wearing an unbuttoned shirt with his arms draped around female students at an Oxford college party started circulating on the Internet
The photos drew a cool response in China were the sons and daughters of the political elite are often perceived to enjoy special privileges and treatment out of reach of most Chinese.
In an open letter published on the Harvard Crimson in April, 2012, Bo hit back at allegations he was living a "party boy" lifestyle.
He denied ever having driven a Ferrari and said that, contrary to reports that he was coasting through his course, earned "a 2:1 degree (Second Class, First Honours) overall and achieved a First in Philosophy."
Bo graduated from Harvard's Kennedy School of Government in May, 2012. He previously attended Oxford, graduating in 2010, and is reported to have recently enrolled in Columbia Law School.