BEIJING China opens a congress of its ruling Communist Party on Thursday that will usher in a once-in-a-decade leadership change against a backdrop of growing social unrest, public anger at corruption and a yawning gap between rich and poor.
More than 2,000 hand-picked delegates will gather at Beijing's cavernous Great Hall of the People for the week-long session, which will see President Hu Jintao give up his role as party chief to anointed successor Vice President Xi Jinping.
Xi then takes over state duties at the annual meeting of parliament in March.
The government has tightened security measures in the run-up to the congress, even banning the flying of pigeons in the capital, and has either locked up or forced from Beijing dozens of dissidents it fears could spoil the party.
Security was especially tight on Thursday around the Great Hall and Tiananmen Square next door, the scene of pro-democracy protests in 1989 that were crushed by the military.
Police dragged away a screaming protester as the Chinese flag was raised on the square early on Thursday.
The party, which came to power in 1949 after a long and bloody civil war, has in recent years tied its legitimacy to economic growth and lifting millions out of poverty.
But China experts say that unless the new leadership pushes through stalled reforms, the nation risks economic malaise, deepening unrest, and perhaps even a crisis that could shake the party's grip on power.
Advocates of reform are pressing Xi to cut back the privileges of state-owned firms, make it easier for rural migrants to settle permanently in cities, fix a fiscal system that encourages local governments to live off land expropriations and, above all, tether the powers of a state that they say risks suffocating growth and fanning discontent.
The congress may also see cautious efforts to answer calls for more political reform, although nobody seriously expects a move towards full democracy.
The party could introduce experimental measures to broaden inner-party democracy -- in other words, encouraging greater debate within the party -- but stability remains a top concern and one-party rule will be safeguarded.