Hong Kongers must accept Beijing's version of democracy even if they think it is imperfect because the interests of the city's business community have to be safeguarded, one of China's foremost legal experts said Thursday.

Wang Zhenmin, a well-connected scholar and regular advisor to Beijing, said greater democratic freedom in the semi-autonomous city must be balanced against the city's powerful business elite who would have to share their "slice of the pie" with voters.

"Universal suffrage means redistribution of economic interests. We have to take care of every class, every group of people, every person, the rich and the poor," said Wang, the dean of Tsinghua University's school of law.

"No one should be left behind, especially those whose slice of pie will be shared with others upon implementation of universal suffrage, which is the business community."

Public discontent in the semi-autonomous Chinese city is at its highest for years, with concern at perceived interference by Beijing and growing divisions over how the next chief executive should be chosen under planned political reforms.

There is also intense anger over continued inequality in a densely populated urban sprawl where a tiny elite still control a disproportionately large chunk of the wealth.

During a talk at the city's Foreign Correspondents' Club, Wang said the city's wealthy must continue to have a say in who leads the territory.

"The business community is in reality a very small group of elites in Hong Kong who control the destiny of the economy in Hong Kong. If we ignore their interests, Hong Kong capitalism will stop (working)," he said.

Beijing has promised the former British colony will be able to vote for its own leader in 2017.

But it has insisted on vetting candidates via a nominating committee, a move activists fear would disqualify anyone critical of the mainland authorities.

Many of those on the current committee -- who chose the city's current chief executive Leung Chun-ying -- are from the city's powerful, pro-Beijing business elite.

- Crucial Beijing gathering -

The top committee of China's rubber-stamp legislature is currently meeting in Beijing this week to discuss a framework of reforms which is expected to be announced on Sunday.

Wang urged Hong Kong's pro-democracy activists to accept Beijing's democratic vision for the city.

"Universal suffrage in any country, any place in the beginning (is) always imperfect," he said. "Less perfect universal suffrage is better than no universal suffrage."

A pro-democracy group, Occupy Central, has pledged to mobilise thousands of protesters to block the financial district if authorities refuse to allow the public to choose their next leader.

Multiple local media outlets, citing unnamed sources, have said the current draft proposal favoured by Beijing for chosing the next leader will limit the number of candidates able to stand and force them to gain a majority from the nominating committee.

That would be unpalatable to many of the city's activists and pan-democratic lawmakers.

Chan Kin-man, one of the Occupy organisers, told AFP that any reforms which violated international standards would be unacceptable.

"If they make a decision that rules out genuine universal suffrage then we believe we will have exhausted all means of dialogue and that we will have to occupy," he said.

Chan said activists would rally on Sunday, when Beijing is expected to have made its decision.

"We will announce our action plan, we will not occupy anything on that date," he said.

Hong Kong was handed over from Britain back to China in 1997 under an arrangement where the city is guaranteed civil liberties and freedom of speech unseen on the mainland.