A HK delegate called the ruling "mild and very clear"

Pro-democracy leaders said the move undermined Hong Kong's autonomy.

They were responding to a decision by a committee of China's parliament that it has a veto over how Hong Kong's leader and legislature should be elected.

It said that while Hong Kong can change its election laws from 2007, it first must obtain approval from Beijing.

The decision rests on an interpretation of territory's mini-constitution, the Basic Law. It effectively means that China can veto any moves to give Hong Kong more democracy, such as direct elections for its chief executive.

HONG KONG RULING Made by the Standing Committee of China's National People's Congress (NPC) or parliament Of over 150 members of the committee, only one is from Hong Kong The ruling accepts the possibility of political change But its stresses that change must be approved by Beijing

Pro-democracy campaigners and legislators said the ruling was aimed at pushing back the prospect of full elections in the former British colony.

"If they can do it now, they are saying 'we will do it as we please in the future'," Democratic Party legislator Martin Lee - who had read the draft document in advance - told the Standard newspaper in Hong Kong.

"If that is so, then no freedom is safe because every clause in the Basic Law is subject to interpretation by the Standing Committee without notice."

James To, another Democratic Party legislator, called the decision "illegal" , because, he said, it amounted to an amendment of the Basic Law without following the correct procedures.

But Tsang Hin-chi, Hong Kong's only delegate on the standing committee, said the ruling should not cause alarm.

"It is very mild and very clear. People should not blindly oppose it, but put the best interests of Hong Kong people first," Mr Tsang was quoted by Reuters news agency as saying.

Hong Kong rallies

The BBC's Louisa Lim in Beijing says the ruling is likely to trigger further protests in Hong Kong.

Friday's protests turned violent in Hong Kong

Some 3,000 people gathered outside Hong Kong's legislature to demand greater democracy as the Beijing committee began reviewing two electoral clauses in the Basic Law on Friday.

"This pits the central government against Hong Kong in an adversarial situation," said Richard Tsoi, an organiser of past protests, commenting on Tuesday's ruling.

"It's not good for Hong Kong's overall stability and development."

Hong Kong's current Chief Executive, Tung Chee-hwa, is supporting Beijing's position.