Thousands of delegates from across China meet this week to seal a power transfer to new leaders who have raised expectations with a deluge of propaganda during their first months running the Communist Party.

Xi Jinping is due to replace Hu Jintao as China's president at the annual National People's Congress (NPC) in Beijing, a rubber-stamp parliament which meets on Tuesday. Li Keqiang will become premier, replacing Wen Jiabao.

It is the final step in a generational handover, four months after they took charge of the ruling party with pledges of cleaner government and greater devotion to people's livelihoods -- themes echoed across state-run media.

Xi's official appointment as president will end months of uncertainty following his appointment as Communist Party leader in November, said Jean Piere Cabestan, politics professor at Hong Kong Baptist University.

"There's a lull of four to five months which partly paralyses the country because the top leaders can't continue to operate the way they did before," he said.

Xi's position in the Communist Party is his real source of power, but his forthcoming government title will give him a more visible role, including on state trips abroad.

Nearly 3,000 delegates gather Tuesday for around 10 days to pass measures pre-approved by party leaders, including a reorganisation of government bureaucracy that will see major ministerial mergers.

The congress is expected to abolish several ministries including the much-maligned railways ministry to try to streamline the bureaucracy.

But such changes are unlikely to rein in the state-owned enterprises which are powerful opponents of market-oriented reforms, Cabestan said.

"Whether it means we'll have more market, fewer monopolies and vested interests remains to be seen... I don't think there will be any fundamental changes."

The NPC may address China's "reeducation through labour" system, which sees petty offenders sent to labour camps without trial. It has come under fire for its abuse by local governments as a way of quashing dissent.

But the degree of reform remains unclear.

Xi and other top leaders have also visited poverty-stricken villages in line with their goal of raising living standards and narrowing the gap in urban-rural inequality -- another public grievance.

To underscore a commitment to economic reforms seen as vital to long-term growth, Xi chose the southern city of Shenzhen -- where China launched its modernisation drive more than 30 years earlier -- for his first official tour as party leader.

But any desire for fundamental reforms is likely to be tempered by the need for consensus decisions and the overriding fear that drastic change could undo the party by disturbing deep-rooted patronage networks.

Xi reportedly warned officials during his southern trip against letting the party unravel like the Soviet Union, saying Gorbachev-style reforms could undermine Communist control.

Signalling a crackdown on graft, which incenses the public, Xi warned it could "kill the party" and threatened to target not only lowly "flies" but also top-ranking "tigers".

"They are trying to improve the system of governance to keep the party in power," said Scott Kennedy, Beijing-based director of the Indiana University research centre for Chinese Politics and Business.

The new premier, Li, will publicly address such concerns immediately after the NPC closes when he holds his only press conference of the year.

Leaders must start meeting the raised expectations, say analysts, or risk exacerbating mounting discontent about corruption, inequality, pollution and other woes.

Public frustration has flared several times since Li took charge over events ranging from media censorship and hazardous smog to China's backing of North Korea after its last nuclear test.

"Having high expectations gives them room and a honeymoon period in which they can do a lot," said Kennedy.

"If we get to next fall and some of the rhetoric and new style doesn't translate into really substantive changes, then I think that the negative reaction will be pretty severe."