China's top security official has urged the ruling Communist Party to resist Western "attacks" on the country's political and legal systems, in comments timed ahead of a 10-yearly leadership change.

Zhou Yongkang, one of China's top nine rulers and reputedly one of the most hardline, said the Communist Party must repel the "mistaken views" of Western political theorists.

"We will never change in our endeavour to defend the party's leading role and socialism with Chinese characteristics," he wrote in the latest edition of a Communist Party publication, "Qiushi".

"We will resolutely resist the attacks of hostile forces on our nation's political and judicial systems, and we will resolutely resist the influence of mistaken Western political and legal views."

Zhou was writing in his position as head of the party's Politics and Law Commission, which oversees China's courts, prosecution and police.

His commission oversees a budget this year of $111.6 billion -- higher than China's declared military budget -- that is used to suppress political opposition, as well as dissidents in Tibet and Xinjiang.

Zhou is regarded as an ally of Bo Xilai, a charismatic party figure whose downfall earlier this year triggered the nation's biggest political scandal in decades.

Bo's dramatic fall has reportedly led to turmoil in China's ruling elite ahead of the transition this year that will see President Hu Jintao, Premier Wen Jiabao and other top leaders give way to a new generation of leadership.

In May, a group of party elders openly called for Zhou's ouster due to his links to Bo, who was removed from the his party post and is under investigation for "serious violations of discipline" -- code for graft.

Bo's wife, Gu Kailai, has also been detained for suspected involvement in the murder of a British businessman, Neil Heywood.

Zhou, 69, has served only one five-year term in the elite standing committee of the party's politburo, meaning he may serve another. However, because of his age, it is unclear whether he will remain in the standing committee.