China's top legislative body decreed Wednesday that Chinese officials could enforce mainland law in part of a new railway station in Hong Kong, despite protests that this would erode the city's autonomy.

A high-speed railway linking Hong Kong to the sprawling southern mainland cities of Shenzhen and Guangzhou is due to open next year.

But the proposal for a joint immigration checkpoint, which would see mainland police and other officials stationed at the new terminus in the heart of Hong Kong, has intensified fears among some that Beijing is tightening its grip on the self-governing city.

The station is sited on Hong Kong's famous harbourfront in Kowloon, not on the border with the mainland further to the north.

The Standing Committee of China's National People's Congress approved the project.

"The NPCSC session said the arrangements are in line with the principle of 'One country, two systems', the constitution and the HKSAR Basic Law," state news agency Xinhua reported, referring to Hong Kong's post-1997 mini-constitution.

The immigration checkpoint would not affect "the high degree of autonomy, nor impair the rights and freedoms enjoyed by residents" of Hong Kong, Xinhua said, adding that the rail link would promote the city's economic development.

Britain handed back Hong Kong to China in 1997 under an agreement which preserved the city's own government and legal system and guaranteed rights and freedoms unseen on the mainland.

But there are fears these rights are being gradually eroded. Beijing has recently stressed its overall authority over Hong Kong.

Li Fei, a high-ranking Beijing official, said Wednesday that decisions by the Standing Committee are "unquestionable" and "have the highest judicial power".

Hong Kong supporters of the rail project say the joint immigration checkpoint will be no different to arrangements overseas such as at the Channel Tunnel.

But pro-democracy politicians in Hong Kong expressed dismay.

Legislator Tanya Chan said the plan was the "most serious violation" of the Basic Law since the handover in 1997.

"This is the first time that the NPCSC spoke out so nakedly to affirm its supreme power over Hong Kong," said Civic Party chairman Alan Leong.

Source: AFP