Teachers in China have been told by the government not to "spread Western values" in their lessons.

A statement released by China's education minister and published by the Communist Party's state news agency warned against any promotion of Western values.

"(We must) strengthen effective management of Western original classroom materials and we must not allow materials into our classrooms that spread Western values," education minister Yuan Guiren is quoted as saying.

The directive comes at a time when China's communist leaders are using subtle but unprecedented force to clamp down on dissent and anything deemed to be critical of them.

"Never allow attacks upon or defamation of Party leaders, or remarks that discredit socialism in university classrooms," Mr Yuan said at a meeting, which was attended by officials from some of China's top universities who received their own "ideological guidance" several weeks ago.

Earlier this month, professors nationwide were warned their lectures would be monitored by party officials and that they should "champion Marxism, traditional culture and socialist values".

The government's official Xinhua news agency said this week that the Communist Party's State Council had ordered ideological teachings to be a strategic part of China's education system.

It added that universities are required to supervise students work to ensure it sticks to the strategy.

Late last year, one Communist Party-run newspaper reported it had sent undercover journalists into university classrooms to expose professors who were critical of the Party or its founder, Mao Zedong.

Western concepts of multi-party democracy, the protection of individual human rights and freedom of expression have been absent from Chinese society throughout the Communist Party's 66-year history.

Under the leadership of President Xi Jinping the core values of Chinese communism have been revived.

Since he took office in March 2013, Mr Xi has emerged as the most powerful Chinese leader since Chairman Mao Zedong.

The number of government critics arrested in the past two years has risen sharply and efforts to censor the internet are unprecedented.