The trial of deposed Communist leader, Bo Xilai, is due to begin on Thursday.
He is accused of corruption, embezzlement and abuse of power. If convicted, he faces the death penalty.
Chinese police have been on crowd control duty near the People’s Court, where the trial will take place, in the city of Jinan in eastern China.
A dozen of Bo’s supporters briefly demonstrated outside before being dispersed by police on Wednesday.
The 64 year old became well known internationally as Minister of Trade from 2004 to 2007.
However the “Red Prince”, as he is known, owes his popularity in China to his previous job as local secretary for the Communist party in the city of Chongquing, in the southern province of Shandong.
Bo is credited with cracking down on the triads and the local mafia as well as restoring egalitarian social programs for the poor.
But, as the champion of China’s new left, he was disappointed with the country’s leadership embracing the market economy, For many his trial is seen as politically motivated.
John Garnaut is author of “The rise and fall of House Bo.” He believes Bo was too much of a threat to the establishment.
“Very little of this case is about corruption per se. But, how Bo was different is that he was really shaking up the political landscape. He was challenging the consensus ideologically. He was threatening, just by sheer force of his political capability and his personality, to overshadow even Xi Jinping, the new Party secretary,” Garnaut said.
In 2012, Bo’s former right hand man, Wang Ki Jun, was found guilty of corruption and sentenced to 15 years in prison.
Jun had also discovered links between the death of British man Neil Heywood and Bo’s wife Gu Kai lai.
At her trial, Gu Kailai, confessed to the murder of Neil Heywood, and was given a suspended death sentence.
Both could be called to testify on Thursday.
As well as bribery and corruption charges, Bo has been accused of illegal wiretapping of senior party leaders, including former President Hu Jintao.
Arrested in the spring of 2012, when he planned to challenge China’s leader Xi Jinping, in the Politburo, he has not been seen in public for 17 months.
His trial is set to be the most sensitive China has seen for three decades.