Chinese President Xi Jinping speaks during the 86th INTERPOL General Assembly at Beijing National Convention Center on September 26, 2017 in Beijing, China. REUTERS/Lintao Zhang/Pool

BEIJING (Reuters) - Communist Party members should study contemporary capitalism but must never deviate from Marxism, Chinese President Xi Jinping said, offering a clear signal there will be no weakening of party control weeks ahead of a key Congress opening.

The party brooks no challenge to its rule, and Xi has overseen a sweeping crackdown on civil society since assuming power almost five years ago, tightening the party’s grip over the internet, media and security infrastructure, and locking up rights lawyers and dissidents.

Speaking at a study session of the Politburo, one of the party’s elite ruling bodies, Xi said that while times are changing and society is developing, the basic tenets of Marxism remain true, state news agency Xinhua said late Friday.

“If we deviate from or abandon Marxism, our party would lose its soul and direction,” Xi said. “On the fundamental issue of upholding the guiding role of Marxism, we must maintain unswerving resolve, never wavering at any time or under any circumstances.”

Xi said the party should better integrate the basic tenets of Marxism with the “reality of contemporary China and learn from the achievements of other civilizations to create and develop Marxism”, Xinhua said.

“Xi also asked Party members to study contemporary capitalism, its essence and patterns,” the report added, without elaborating.

China has transformed its economy since it began landmark reforms in the late 1970s, and is now the world’s second-largest economy. Private firms are now supported and encouraged, but the state-owned sector remains a major driver of growth and investment, though some industries like iron and steel are suffering from worryingly high levels of over-capacity.

Xi said the party must continuously develop socialism with Chinese characteristics, continuously enhance China’s comprehensive national strength and fully demonstrate the advantages of China’s socialist system.

Next month’s party Congress, which opens on Oct. 18, will see Xi further cement his grip on power and usher in a new generation of senior leaders.