Beijing (CNN) -- The Communist Party's 18th National Congress enters its second session Friday, a day after President Hu Jintao warned that a failure to deal with corruption could bring down the party and the state it controls.
Hu spoke at a key meeting of top officials who will usher in a new set of leaders of the world's most populous nation. After a decade in power, Hu is expected to hand over the party's top job to Vice President Xi Jinping.
"If we fail to handle this issue well, it could prove fatal to the party and even cause the collapse of the party and the fall of the state," Hu said of corruption during his speech at the start of the congress in the Great Hall of the People in the heart of the Chinese capital.
His comments to a vast room of delegates stood out in light of the huge political scandal that has rocked the party this year.
The controversy involved former high-flying politician Bo Xilai, who is under criminal investigation after being ousted from his posts and the party itself. He is accused of corruption, abuse of power and improper sexual relationships; official news reports have said Bo made "severe mistakes" related to the killing of a British businessman -- a crime for which Bo's wife was imprisoned -- and a diplomatic incident involving his former police chief in Chongqing.
More than 2,200 delegates from across China gathered for the congress. They will select the 200-plus members of the party's Central Committee, who in turn appoint the Politburo and ultimately the all-powerful Politburo Standing Committee, the country's decision-makers.
But most, if not all, of the outcomes are predetermined after a long period of secretive deal-making between party power brokers.
The congress itself meets every five years. It is designed to assess the country's progress and set new directions. Every 10 years, it selects the new leadership.
This year, the legacy of the Hu years is under the microscope. Under Hu and Premier Wen Jiabao, China's economy has continued to grow, lifting tens of millions of people out of poverty.
China is now the world's second-biggest economy and closing fast on the United States. But there have been disappointments and discontent along the way, and Hu's much-vaunted "harmonious society" is showing signs of cracking.
Chinese leaders have endured a tumultuous year. The veil of secrecy around the party has been lifted, with reports of rifts and infighting. And the fall of Bo brought about China's biggest political scandal in decades.
Bo, once party chief of the massive metropolis of Chongqing, is now in disgrace awaiting trial. His wife, Gu Kailai, is in prison, convicted of murdering a British business associate.
China is straddling many fault lines: a widening gap between rich and poor, rising unrest about issues like pollution and land seizures, and a slowing economy that some say is in need of serious reform.
Another issue Hu's government has struggled to tackle during its decade in power is the discontent and unrest among Tibetans living under Chinese rule.
Authorities were given a grim reminder on Wednesday of the disillusionment and desperation of many Tibetans in western areas of China after four people set themselves on fire to protest Chinese rule.
One teenage Tibetan monk died and two were injured after self-immolating in a majority Tibetan region of Sichuan Province, said Penpa Tsering, a spokesman for the Tibetan parliament in exile in Dharamsala, India. And a 23-year-old Tibetan woman died a separate incident in Qinghai Province, Tsering said, citing unidentified people in Tibetan areas.