BEIJING - A key conclave of China's Communist Party elite kicked off Monday in Beijing, the official Xinhua news service reported, as leader Xi Jinping seeks to tighten his control over the organisation.

Nearly 400 top members of the world's most powerful political party have gathered at the exclusive Jingxi Hotel to discuss changes to party structure and management for four days.

They will focus on reforming the "norms for political life" and the party's internal rules for supervising cadres, Xinhua said.

The dry rhetoric around the Sixth Plenum, as the meeting is known, hides what may be a ferocious, high-stakes battle for control over the world's second-largest economy.

"This year's plenum on party-building is key to Xi's entire political project, and could very well turn out to be the most important of his first term," said Trey McArver, China analyst at Trusted Sources.

It "looks certain to further consolidate his grip over the party", he added.

Since taking its helm in 2012, General Secretary Xi Jinping has sought to bend it to his will, and taken control of more levers of power than any leader since Mao Zedong.

His most powerful tool for bringing the party to heel has been an anti-corruption campaign that is now "the longest-lasting, (and) widest-ranging in party history", McArver said.

The party's Central Commission for Discipline and Inspection, its feared internal watchdog, said at the weekend that between 2013 and last month, more than one million members had been punished for graft. China's ruling party has 88 million members.

Xi has felled top generals in the People's Liberation Army and seemingly invincible bastions of power such as former security czar Zhou Yongkang, eliminating potential rival sources of power.

But it has laid waste to the party's organisational chart, paralysing grassroots bureaucrats petrified of making a mistake, a problem compounded by unclear and contradictory signals on what policies to pursue.

New policies will seek to address "outstanding problems" and compel senior leaders to be a good example for lesser officials, Xinhua said.

That could mean tightening regulations governing cadres' behaviour and strengthening enforcement, analysts say.

Xi has described the party as a "magic weapon" that can be used to implement reforms necessary to achieve his goal of the "Great Rejuvenation" of the Chinese nation, an idea that he frequently describes as the "Chinese dream".