At the same time, Xi unveiled a new leadership team which did not include any obvious successor, increasing speculation he may hold on to power at the end of his second five-year term as President.

Margaret Lewis, an expert in China's legal system at National Taiwan University, said Xi had already scored a "major political victory" with the addition of his "Thought" to the party constitution, and "does not need to change the rules on term limits to remain extremely powerful."

Unlike the presidency, there is no restriction on how long Xi could serve as CCP General Secretary, the position from which his true power flows, though traditionally both titles have been held by the same person.

Deng Xiaoping, during his time as leader, gave up most official positions but retained a huge amount of control over decision making, Lewis said.

"Titles matter, but there is more to power in China," she said, particularly the "extent to which other top leaders act as a check on his power."

"Xi has shown firm faith and will, clear commitment to the people, extraordinary political wisdom and tactics and a strong sense of responsibility, in leading the CPC and China in the great struggle with many new contemporary features," the Politburo said in a statement following the "meeting of self reflection."

William Nee, a China researcher for Amnesty International, said self criticism meetings "are a very old tool ... to get people to admit their faults publicly, talk about the problems in their work styles and to profess loyalty to the party center and in this case explicitly to Xi Jinping."

Lewis said the session was typical of how under Xi "there is little tolerance ... for the slightest wobbling off the party line."

Constitutional changes

Creation of the National Supervision Commission would expand that discipline and control to a broad swath of society, analysts said.

Tackling corruption has been a major priority for Xi, but it has previously been focused on party bodies and the military, attracting considerable public support even as some critics accused him of using the campaign to go after potential rivals and shore up his power base.

That system would apply not only to party members, but also to people working in state-owned companies, scientific research, education, healthcare and other public bodies, in what Nee described as a "very worrying" development.

The NSC is one of several new laws which "give the party and the government sweeping powers," he said.

While much of these changes involve legalizing activities which already go on unofficially, Nee said this may be motivated by a desire to gain international legitimacy for and cooperation with China's anti-corruption drive.

"One sticking point for a lot of countries in repatriating allegedly corrupt officials is the (existing system) is technically an extra-legal body," Nee said.

Military might

"The importance of the Party's control over the military is an oft-repeated phrase, but Xi has emphasized it heavily during his tenure," Tom Rafferty, China manager at the Economist Intelligence Unit, told CNN earlier this year.

The People's Armed Police (PAP) are often deployed to tackle riots, large-scale protests and terrorist attacks, and are "very involved in the maintaining of social order," Nee said, particularly in Tibet and Xinjiang, both of which have large non-ethnic Chinese populations and history of protests and unrest.