A stronger grip on power could allow Hu to speed up his drive to balance breakneck but uneven economic growth, improve the lives of poor farmers, build a social safety net, halt rampant environmental degradation and promote “fair and just” policies.

The 58-year history of the People's Republic is littered with the names of heirs apparent who died in prison, in mysterious circumstances or under house arrest. This time, when the 2,217 party delegates pack into Beijing's Great Hall of the People, the all-important question is whether Hu, who doubles as state president, can neutralise Jiang's lingering off-stage influence.

“Hu is now the biggest stakeholder and hopes to become the majority stakeholder,” political commentator Liang Kezhi said. Even in the months before the congress there have been high-level political casualties.

A top-ranking rival, the Party boss in Shanghai, Jiang’s traditional power base, now faces trial for corruption. The finance minister resigned amid allegations of a sex scandal. The food and drug safety chief was tried and executed for corruption.

But the 81-year-old Jiang’s influence, while waning, has not been eclipsed. One key test of Hu’s growing confidence will be whether he can ease out Jiang allies Zeng Qinghong and Jia Qinglin from the all-powerful Politburo Standing Committee, now down to eight members after the death of another Jiang loyalist, Vice Premier Huang Ju, in June.

“Zeng Qinghong has too much power. He controls the Party’s assets and cadres nationwide,” one source with ties to the leadership said of China's sitting vice president. Another barometer of Hu's clout is whether he can name a protege as his successor — a fifth-generation leader after Mao Zedong, Deng Xiaoping, Jiang and Hu himself.

Li Keqiang, Party boss of the northeastern rustbelt province of Liaoning, is front-runner and tipped to join the Standing Committee, sources with leadership ties said. The congress will also be a coming-of-age event for “princelings”, the sons and daughters of incumbent, retired and late leaders. A record number of these are tipped to join the decision-making Politburo, one notch below the Standing Committee, the sources with leadership ties said.

Candidates include new Shanghai Party boss Xi Jinping, Commerce Minister Bo Xilai and Li Yuanchao, Party leader in the eastern province of Jiangsu. Analysts say Hu, 64, who doubles as party and military chief, has shown surprising political skills, achieving more in five years than Jiang did in the same period.

To that end, the congress may also enhance Hu’s political status. Before retirement, state media hailed Jiang as “the core” of his generation of leaders, a title Hu did not inherit. “Hu will be the core after the 17th congress, ushering in his era” a second source with leadership ties told Reuters. But analysts said that Hu, while politically stronger, is no strongman like Mao or Deng. “Today, one person cannot call all the shots,” Liang, the commentator, said.