China's parliament passed national security legislation for Hong Kong on Tuesday, the city's Cable TV reported, setting the stage for the most radical change to the former British colony's way of life since it returned to Chinese rule in 1997.

Cable TV, citing an unidentified source, said the law was passed unanimously by the Standing Committee of China's National People's Congress.

Beijing introduced the law in response to last year's often-violent pro-democracy protests in the city. It will tackle subversion, terrorism, separatism and collusion with foreign forces, officials have said.

A draft of the law, which will come into force as soon as it is gazetted in Hong Kong, has yet to be published.

South China Morning Post reported that the new law is expected to carry a maximum penalty of life in jail, rather than the previously expected 10-year maximum.