JINAN, China -- Bo Xilai, the politician who fell from the heights of China's elite, took a pugnacious and defiant stand on Thursday in the opening session of China's most closely watched trial in decades, denying that he took millions of dollars in bribes and ridiculing his wife's testimony against him.
According to lengthy transcripts the court released in an extraordinary show of transparency, Mr. Bo, 64, called his wife's assertions that she had noticed anonymous deposits in their bank account "laughable." He accused a businessman who had recorded video testimony against him of having "sold his soul." And he discounted his earlier confession to taking bribes, saying he had made the statements to Communist Party investigators against his will, out of "opportunism and weakness" and under "mental strain."
The authorities' unexpected openness about the trial, including allowing a running court microblog and social media updates by state media organizations, turned what many had expected to be banal theater into a showcase of Mr. Bo's defiance.
The dramatic day raised questions about how party officials would continue to steer a delicate political process that has captivated Chinese scrutinizing it on the Internet.
Officials set up a press center in a hotel across the street from the court in this eastern provincial capital. There, dozens of foreign journalists and a handful of reporters for Chinese state media gazed at large-screen televisions streaming the court microblog feed. When the first photograph from the trial was posted before 11:30 a.m., showing the 6-foot-1 Mr. Bo standing with a bemused look between two towering police officers, journalists charged the televisions and snapped photos.
Dressed in a white shirt and black pants with his hair neatly trimmed, Mr. Bo displayed some of the showmanship he deployed in climbing to the party-chief post in Chongqing municipality and the elite Politburo, before he was felled last year by a scandal involving the death of a British businessman, a case in which his wife, Gu Kailai, was convicted of murder. Mr. Bo is also charged with abuse of power over allegations he obstructed an investigation into the death, and with embezzlement.
There were limits to the transparency. One person briefed on the proceedings said that some court testimony did not appear in the released transcripts. And by evening, censors had sanitized the comments section of the Jinan court microblog, so that many remarks skeptical of the justice process had been removed.
Analysts said that publicizing the hearing was the party's attempt to lend legitimacy to a trial in which a guilty verdict and long prison sentence are almost certainly preordained.
The hearing was not as public as the notorious trial in 1980 of the Gang of Four blamed for the havoc of the Cultural Revolution, which was televised. But officials issued about 60 real-time updates over the court microblog, eliciting bursts of online commentary.
"This is the most open trial of its kind, certainly the most open among the ones we have seen recently," He Weifang, a liberal law professor at Peking University, said in a telephone interview. "He seems to be speaking his mind, judging from his speech and the words he used."
But over all, he added, "the whole court is controlled by Beijing."
On Twitter, Nicholas Bequelin, an Asia researcher for Human Rights Watch, said, "Even though Bo rejects the accusations against him, he is still playing ball in what is, in essence, a scripted piece of political theater."
The party's efforts at forging an aura of legitimacy could backfire. If evidence released during the trial proves flimsy, the public could side with the defiant Mr. Bo, whose Maoist slogans and new brand of socialism bolstered his popularity in Chongqing.
Mr. Bo insisted that he knew nothing of a villa on the French Riviera that prosecutors said Ms. Gu bought in 2000 with $3.2 million from Xu Ming, a young tycoon, or about a hot-air balloon venture between the two. He denied knowledge of a $16,000 trip to Africa made by his youngest son, Bo Guagua, and his friends; an $18,000 Segway-like vehicle that Mr. Xu bought for the son; and $50,000 of debt on the son's credit card that Mr. Xu paid off.
He said he did not know much about his wife and son's expenses, because Ms. Gu was "a person of culture and taste, a modern intellectual woman," so they did not discuss money.
"I think the prosecutor appeared to be ill-prepared," Mr. He, a critic of Mr. Bo's past policies, said in the interview, echoing a sentiment widely seen online. "In comparison, Bo appears to be more authentic."
Since Mr. Bo was dismissed from his party chief post in March 2012 and placed under house arrest, party leaders have been concerned about his command of popular support. Some of the ardor among ordinary Chinese was in evidence on Thursday morning, as Bo supporters, some carrying Mao Zedong posters, showed up in Jinan at courthouse barricades guarded by the police.
"I'm willing to do anything for him," said a farmer, He Demin, 51, who had flown in from Chongqing the previous night. "With him gone from Chongqing, security and morale have plummeted. We so need a person like him."
As four minivans with tinted windows sped into an entrance of the courthouse compound, the farmer sprinted toward them, waved his hands and bowed in their direction. "I bow to you," he said, meaning to address Mr. Bo, in case he was in the convoy.
Mr. Bo started becoming combative midway through the morning session. Prosecutors charged that he had taken about $180,000 in cash bribes from a state company manager and longtime associate, Tang Xiaolin, in exchange for land and auto transactions that Mr. Bo granted as a top official in the northeast province of Liaoning. After watching video testimony from Mr. Tang, Mr. Bo said: "I really saw the ugliness of a person who sold his soul," and, "He's biting wildly like a mad dog."
Prosecutors also read related testimony from Ms. Gu, in which she said she had noticed anonymous deposits being made into an account she shared with Mr. Bo. "I think Gu Kailai's testimony is very amusing and very laughable," Mr. Bo said.
In the late afternoon, Mr. Bo and his lawyer parried the testimony of Mr. Xu, the young tycoon, who appeared in court and is accused of giving Mr. Bo's family $3.4 million in bribes, mostly for the purchase of the French villa.
Some analysts say Mr. Bo's outbursts could be part of a bargain, in which he would accept the inevitable prison sentence in exchange for a chance to speak his mind, to a degree. All the information, including the official microblog posts, were still controlled by officials who generally knew what to expect, the analysts noted. The trial is scheduled to continue on Friday, when prosecutors are to present evidence on the charges of embezzlement and abuse of power.
On Thursday night, Li Wangzhi, the son of Mr. Bo from his first marriage, who was in the courtroom, released a statement that said, "I thank the party central authorities and the court for giving the defendant greater rights to a defense and freedom than he had expected, allowing my father to speak his true mind."
Mr. Li added that his father had "stood by his own ideas" through an investigation that lasted 500 days and involved more than 300 people.
Chris Buckley contributed reporting from Hong Kong. Patrick Zuo contributed research from Jinan, and Mia Li and Shi Da from Beijing.
Correction: August 22, 2013, Thursday
This article has been revised to reflect the following correction: An earlier version of this article referred incorrectly to testimony from Gu Kailai, Bo Xilai's wife. It was read aloud in court at Mr. Bo's trial; it was not presented via video.
This article originally appeared in The New York Times.