Sun, 54, was sacked as Communist Party boss of the megacity Chongqing in July and placed under investigation for corruption in the run-up to the party’s national leadership reshuffle in October.

Prosecutors accused Sun of taking advantage of his position to seek profits for others and of illegally accepting 170 million yuan in assets, directly or via his designated parties, Xinhua reported.

The prosecutors said the charges related to crimes he allegedly committed during his time as a district party boss in Beijing in 2002, while he was minister of agriculture, and his stints as party chief in northeastern Jilin province and Chongqing.

Court hearings against political heavyweights like Sun are largely a formality in China where the party keeps a tight grip on the judiciary.

Sun had already been punished by the party’s internal corruption watchdog for breaking party discipline and was widely condemned by state-run media for his alleged wrongdoings before he appeared in court.

After the court session on Thursday, party mouthpiece People’s Daily said in a staff commentary that the trial reflected the continued momentum of Xi’s anticorruption crusade.

“It again sends a clear signal to the outside world: there is no ‘special party member’ when it comes to party discipline and the law,” it said.

Sun was the youngest member of the Politburo before he was expelled and was once widely considered a strong candidate to sit on the Politburo Standing Committee, made of up China’s top leaders.

After the accusations were levelled at Sun he was replaced in Chongqing by Chen Miner, a protégé of President Xi Jinping and a rising political star.

During China’s annual parliamentary sessions in Beijing last month, Chen lashed out at Sun for “complying in appearance but opposing in his heart” central government policies.

“Sun did follow [the central leadership’s line] when he was reading from the script, but he had never done so in his heart,” Chen was quoted as saying by Chinese media.

After the parliamentary meetings, Chongqing’s official newspaper published a series of articles criticising Sun’s record in the city.

His wrongdoings included launching projects nominally aimed at improving people’s livelihoods, but delivering no results; being apathetic to people’s suffering and safety by not showing up at disaster scenes; and distorting central government policies in their implementation to fit his own ideas, the reports said.

Sun is one of the most senior serving politicians to be snared in Xi’s anticorruption campaign.

Huge numbers of officials have been prosecuted, although some critics argue that the campaign has also been used to purge the president’s political rivals and instil fear and loyalty in the party ranks.

The court in Tianjin has previous experience in hearing cases against political heavyweights brought down in the anticorruption campaign.

They include the retired Politburo Standing Committee member and security tsar Zhou Yongkang and former presidential aide Ling Jihua.

Both are serving life sentences for taking bribes, illegally obtaining or leaking state secrets and abuse of power.