The Seventh Plenary Session of the 17th Central Committee of the Communist Party of China (CPC) on Sunday endorsed a decision made by the Political Bureau of the CPC Central Committee to expel Chongqing's former Party chief Bo Xilai from the Party.

The session also supported the Party authority's decision to expel former Chongqing vice mayor and police chief Wang Lijun, who in September was sentenced to 15 years in jail for crimes including trying to cover up the murder case involving Bogu Kailai, Bo's wife, the Xinhua News Agency reported.

The announcement came several days ahead of the CPC's 18th National Congress, and is considered the latest move to show the Party's unity and resolution in fighting corruption.

"Taking away Party membership is the most serious punishment for an official," said Lin Zhe, a professor of anti-corruption studies at the Party School of the Central Committee of the CPC. "The move demonstrates the Party's determination to fight corruption during the power transition."

Bo's case was transferred to prosecutors last month for "suspected crimes." He was expelled from his post in Chongqing in March and later by the CPC Central Committee's Political Bureau.

Authorities announced on September 28 that Bo was found to have taken "huge amounts" of bribes, abused his power, and had improper sexual relations with several women during his terms heading the Dalian city government, the Liaoning provincial government, the Ministry of Commerce and Chongqing, according to Xinhua.

Lin said she is expecting a trial soon and the announcement of a sentence shortly after, based on the authorities' swift handling of the Bogu Kailai and Wang Lijun cases.

Two months ago, Bogu was charged, tried and sentenced to death with a two-year reprieve for murdering British citizen Neil Heywood. The entire process took less than a month.

The Party's disciplinary head He Guoqiang named Bo in October during a speech about the Party's anti-corruption efforts. He mentioned Bo along with Wang Lijun and former Shenzhen mayor Xu Zongheng, who was sentenced to death with a two years reprieve for taking bribes.

Lin said Bo's fall serves as a big lesson for other officials.

"No matter how senior your position is, or how good a job you've done at your posts, the bottom line is that you cannot become greedy," Lin said.

Wang Minggao, an anti-graft scholar with Hunan Business College, said regulations to prevent officials from corruption, such as those which require officials to report their income and properties to authorities, still need improvement.

"None of the officials brought to justice was exposed by the existing income report system," Wang said. "Although it's impossible to publicize all officials' incomes at once, eventually, officials' possessions have to be open up to the public, just as many other countries do."

Lin said the Party has been making progress in anti-corruption efforts and believes more effective prevention measures will be put in place step by step.

Bo Xilai's rapid fall

March 15 Removed from his post as Party chief in Chongqing and as a member of the CPC Chongqing municipal committee
April 10   Membership of the CPC Central Committee Political Bureau and the CPC Central Committee suspended for serious violations of discipline
September 28 Expelled from the CPC and removed from public office
October 26 Deprived of his post as a deputy to the National People's Congress; put under investigation for alleged criminal offenses and imposed coercive   measures
November 4 Expulsion from the CPC endorsed by the Seventh Plenary Session of the 17th Central Committee of the CPC