China's apparent decision to throw the book at disgraced politician Bo Xilai is aimed at killing support for a leader at the core of a scandal that tarnished the Communist Party and threatened its cherished unity, analysts said.

China said Friday that the former rising political star would "face justice" for a litany of crimes including abuse of power, bribery and "improper sexual relationships" -- an unprecedented rebuke for a top Communist official.

Allegations of graft and other lurid details in a scandal that has already seen Bo's wife convicted of murder have caused divisions within the secretive party ahead of a sensitive leadership transition, observers said.

Residual support for the charismatic Bo has worried a Chinese leadership that insists on total allegiance to the course set by the party, and the attack on Bo is meant to exterminate it, they said.

"Bo Xilai could have become a populist hero, which would have been bad for current leaders... it's enough to name his crimes to shatter the illusion of Bo as a heroic figure," said Zhang Ming, a political scientist at Renmin University in Beijing.

Bo, a former commerce minister and party boss of the megacity of Chongqing, was known for his suave and open demeanour, unusual in a country where leaders are typically rigid bureaucrats, and for his open lobbying for promotion to the top national leadership.

But this irritated many in the Communist Party and violated a code against naked ambition and other ill-discipline -- a lesson learned from the divisive and disastrous political campaigns of Communist founder Mao Zedong.

Bo's populist style of leadership included a nostalgic revival of Mao-era "red culture" that, along with a high-profile crackdown on organised crime in Chongqing, had wide popular appeal.

"I think that (Chinese president and party chief) Hu Jintao has scored some kind of victory because Hu and (Premier Wen Jiabao) wanted stiff punishment against Bo as opposed to some party elders and Maoist elements," said China politics analyst Willy Lam.

The scandal, which first emerged earlier this year, came at a highly sensitive time as the party prepares for a once-a-decade transition to a new set of top leaders that will be unveiled in a congress opening on November 8.

Despite intense internal jockeying for top positions, an outward image of unity is considered sacrosanct.

But Zhang noted that some protesters in recent anti-Japan demonstrations over a disputed island chain carried banners that voiced support for Bo, which he said "alarmed many people in the party".

China's leaders were believed to be fiercely debating what to do with Bo, a risky business since airing details of impropriety would highlight official graft -- a source of public anger amid regular reports of corrupt and high-handed officials.

The fierce internal bargaining amongst China's ruling elite likely has influenced the leadership selection, although it is impossible to know for sure given the party's renowned secrecy, observers say.

Bo's supporters are thought to be identified with conservative forces backing greater state involvement in the economy.

They apparently "have agreed to let him be thrown to the wolves in exchange for whatever deal they have got in the leadership change", said Steve Tsang, professor of contemporary Chinese studies at the University of Nottingham.

Patrick Chovanec, from Tsinghua University in Beijing, said that destroying an official's career by airing corruption allegations "was always a strategy to completely vilify whoever is getting purged, and therefore the message was really about cleansing itself of a bad apple".

"They are going after him with both barrels," he added.

Analysts say a lengthy prison sentence -- possibly life -- is likely. It is not known when Bo might be officially charged or tried.

The scandal, which saw Bo's wife Gu Kailai hit with a suspended death sentence in August for murdering a British businessman over a soured deal, has provided a glimpse into the wealthy lifestyles of China's power elite.

A day after state media painted Bo as an unscrupulously corrupt villain, Premier Wen called for Chinese to "rally more closely around" the party leadership, although his statement did not mention the Bo affair.

But casting Bo as bad egg will be a tough sell amongst ordinary Chinese who increasingly view the party as being rife with corruption.

"Ordinary people will never know the truth of these allegations, but I reckon there are many others in the same position as Bo who behave in the same way," wrote a user on leading portal Sina.com's popular microblogging service.

"All government officials have corruption problems," wrote another.