Communist Party committee members Li Zhanshu (L) and Zhao Leji at the 12th National People's Congress in Beijing on March 5, 2015.

President Xi Jinping's trusted ally Li Zhanshu stands a good chance of becoming chairman of China's parliament while Communist Party organisation chief Zhao Leji is likely to head its corruption watchdog, sources have told the South China Morning Post.

Li is widely expected to be elevated to the Politburo Standing Committee – the ruling party's top echelon of power – on Wednesday, a day after the party's 19th national congress closes in Beijing. Most observers had predicted he would succeed Wang Qishan as anti-corruption tsar.