A group of Chinese intellectuals has called on the government to implement urgent political reforms and respect human rights or risk "violent revolution".

In an open letter 71 top academics warned that growing economic imbalances were fuelling social unrest and an uprising could erupt if reforms were not implemented immediately, Hu Xingdou, one of the signatories, told AFP Monday.

"If urgent systematic reforms needed by Chinese society continue to suffer setbacks and stagnate, then official corruption and social dissatisfaction will boil up to a crisis point," said the letter, posted on the Internet last week.

"China will once again miss the opportunity for peaceful reform, and slip into the turbulence and chaos of violent revolution."

The document was reminiscent of Charter 08, a daring call for political reform in 2008 that was largely penned by dissident Liu Xiaobo. He was sentenced to 11 years in jail the following year for inciting subversion.

In 2010 Liu was awarded the Nobel Peace Prize, an act that incensed China's Communist rulers.

While the latest call for reform steered away from Charter 08's advocacy of western-style democracy, it called on the Communist Party fully to implement the freedoms of speech, press and association that are protected by the constitution but routinely ignored by the authorities and police.

"Once we go against the tide of democracy, human rights, rule of law and constitutional government, the people will suffer disaster and social and political stability will be impossible," the letter said.

Hu, a noted economist at Beijing Institute of Technology, said most of those who signed the letter were academics who have worked for the government. He played down the possibility that authorities would launch a crackdown on them.

He added that the letter was organised to support a recent vow by China's newly appointed leader Xi Jinping to implement the rule of law and legal restraints on the party, whose image has been tarnished by a series of graft scandals.

"Our letter is friendlier, rational and gradual... it is a reaction to the speech by General Secretary Xi Jinping on implementing the authority of the constitution, so this is not the same as Charter 08," Hu said.

"In the race between reform and revolution, we must quicken the pace of reform in order to avoid the violence of revolution."