President Xi Jinping is expected to be handed a historic third term in control of China on October 23, it emerged on Saturday, after a spokesman confirmed the Communist Party's 20th Congress will end the previous day.

About 2,300 party delegates from every province will gather at the Great Hall of the People in Beijing from Sunday for the mostly closed-door conclave, to rubber-stamp the country's next leadership make-up.

The five-yearly talking shop will get under way at 10:00 am (0200 GMT) with an opening ceremony, after which Xi is expected to deliver a lengthy speech that will give an assessment of the previous term as well as a roadmap for the next five years.

Should everything go to plan, after the week-long meeting 69-year-old Xi will be reconfirmed as the party's general secretary, cementing his position as China's most powerful leader since Mao Zedong.

At the highly choreographed conclave, the 2,296 participants will also pick members of the party's roughly 200-member Central Committee, which in turn selects the 25-person Politburo and its all-powerful Standing Committee -- the country's highest leadership body.

The day after Congress closes, the new Standing Committee -- currently a group of seven men including General Secretary Xi -- should be revealed, if this year follows the same convention as previous Congresses.

Congress spokesman Sun Yeli confirmed the closing date of October 22 and told reporters: "The preparations for the Congress have now been fully completed."

During the two-hour press conference -- in which Chinese state media asked several questions, as well as some international outlets -- Sun said the proportion of female delegates had increased to 27 percent, from 24 percent at the last Congress in 2017.

There were no questions asked about Xi.

China is holding Sunday's opening ceremony under a strict zero-Covid policy, sealing organisers and journalists in a virus-secure bubble two days in advance.

Participants have been ordered to take daily Covid-19 tests to attend events, some of which are being held remotely by video link instead of in person.

At a hotel in western Beijing, organisers have set up a press centre crammed with exhibitions extolling Xi, festooned in the Communist Party's signature red and gold.

Scattered around the venue are tables piled with books on Xi's philosophy and China's development, while one display features an AI-driven "digital human" that tells jokes and sings songs upon request.