Before it started, Bo's trial was expected be very brief and scripted, like the trials of other purged senior officials. A quick confession and lenient sentence were anticipated.

That the trial was so lengthy, with Bo fighting all three charges against him and seeking to overturn his pre-trial confession, and that the proceedings were relatively open, with the court drama unfolding through official microblogs, albeit redacted, for the first time were a surprise to many.

"Ninety-nine per cent of the facts the prosecutor just stated have nothing to do with me or my case," Bo said on the first day, according to an official transcript.

But the unusual performance in fact came as no surprise to senior party leaders. Bo said he had told officials in a pre-trial meeting on August 14 - eight days before the trial began - that he disagreed with the charges against him, meaning officials were aware of how he would act in court.

A source told the Post a week ahead of the trial that Bo would deny all the charges, saying: "Bo has been calling for an open trial in order to defend his honour." Another person close to Bo's family said the authorities were satisfied with the outcome.

The person explained that Meng Jianzhu , the nation's security tsar, who arrived at Jinan on the eve of the trial to ensure it went smoothly, praised the work of court officials in a meeting after the first day.

Analysts say that such a display of approval indicated the party's elite, anxious to win support from a public angered and demoralised by growing corruption, had already made some sort of an agreement with Bo.

"I would be surprised if no deal was made beforehand," said Steve Tsang, director of the China Policy Institute at the University of Nottingham.

"Bo was not challenging the party leadership for putting him on trial just because he had lost in a power struggle, which would be political defiance and unacceptable to the leadership. He was merely challenging the evidence against him which, for the leadership, was tolerable."

Jonathan Holslag, head of research at the Brussels Institute of Contemporary China Studies, agreed and said there had been some degree of understanding between Bo and the political leaders of the party about what to say and what not to say.

"The party has been basically able to use this trial as an opportunity to show its willingness to combat corruption, and also to show to the rest of the world that China can handle such a very sensitive case in an open, transparent and fair manner. That explains what the interest is for the party."

It would have been against Bo's nature not to turn his show trial into political theatre, said Beijing-based historian Zhang Lifan, and that could have formed part of negotiations with the party, if there were any.

"Bo Xilai is a natural born politician and political power is all he wants. It would have been the end of his political career if he had admitted the charges, and his life would have become meaningless, even if he had received a lenient sentence," Zhang said.

"The trial could have been his last public show, and he had to defend himself if he wanted to have a place in history as a spiritual leader of Chinese conservatives."

Bo, 64, had long been seen as a thorn in the side of the country's current leadership. He has become a hero to the nation's conservatives for his aggressive mass campaigns venerating Mao Zedong .

"He represents a certain grouping of political power that the top leadership cannot absolutely ignore," said political analyst Chen Ziming .

"To reveal the details of the case to the public shows the leadership was playing tough and was confident of managing all the potential outcomes."

President Xi Jinping has maintained the image of a tough politician. Since taking office he has launched various campaigns, including one focusing on "three self-confidences" - encouraging citizens to have confidence in China's political system, in the party line and in party theory.

"The trial echoed Xi's view that China could have a relatively transparent judicial system under the control of the party," Chen said.

To play down Bo's defiant performance in court, the government was keen to control information. Updates on the proceedings were filtered before being published on the court's microblog. It also used traditional state-owned media to defame Bo as a corrupted, demonic figure.

"The release was tightly controlled and indeed organised by the authority," Tsang said.

"The party is certainly trying to use the microblog releases to project a certain image of itself."

Kerry Brown, director of the China Studies Centre at the University of Sydney, said: "The treatment of the trial shows that the party has become more adept at trying to manage news like this and to get out some of its messages. I don't think it means a new era of transparency and openness. The fundamentally important issue for me in all of this is that Bo's real death sentence was last year when, after so much work and effort, he was removed from a chance of being on the [Politburo] Standing Committee."

Brown added: "This is why what happens now is almost irrelevant. He had what he most wanted - power - taken from right before him, and that would hurt more than any of this process and sentencing."