Hong Kong goes to the polls Sunday to elect a new legislature that will lay the ground rules for direct elections, amid growing disquiet over mainland China's hold over the former British colony.

The vote is taking place against a steady drumbeat of anti-government protests, fueled by resentment over what many see as the ruling elite cozying up to Beijing at the expense of Hong Kong's cherished democratic freedoms.

The Legislative Council's next four-year term will set the stage for one-person, one-vote leadership elections in 2017, when Beijing has promised universal suffrage in the territory for the first time.

In 2020 it has promised to extend that to elections for the legislature, indicating it will do away with a complicated voting system which ensures pro-Beijing parties and candidates dominate the city's government.

But pro-democracy parties say China's communist rulers have no intention of easing their grip on the regional financial centre, and are suspicious about what form of "universal suffrage" the pro-Beijing executive will propose.

They fear that if the opposition stumbles in the weekend polls, the government will be able to force through anti-democratic measures that would dilute the effects of a direct vote.

"If the pan-democrats are able to muster half of the 70 seats, they will be able to galvanise enough support to enable universal suffrage to take place in 2017," Chinese University of Hong Kong political analyst Willy Lam said.

But if they lose the one-third they currently hold, they will be unable to prevent the establishment camp "bulldozing through anti-democratic bills", he added.

The Beijing-backed government has been mired in scandal and controversy since it took office in July under the leadership of former property surveyor Leung Chun-ying.

Its key legislative challenges include making good on promises to boost public housing to address soaring property prices, and closing legal loopholes to stop pregnant mainlanders from swamping the city's public hospitals.

Up to 90,000 people demonstrated in July against a plan to introduce "national education", shortly after some 400,000 anti-establishment demonstrators took to the streets during a visit to the southern city by Chinese President Hu Jintao.

Students have been camped outside the government headquarters for a week, accusing Leung of planning to "brainwash" Hong Kong's children with Communist Party propaganda.

Leung denies the allegations, and he has the support of pro-China parties which are staunch backers of the so-called patriotism classes.

"The recent events show that many Hong Kong people are very fearful of communist rule and they feel that the communist government is interfering too much," Democratic Party vice chairwoman Emily Lau told AFP.

Pro-democracy candidates have been conspicuous on the streets, handing out how-to-vote cards and filling busy intersections with posters and fresh-faced campaign workers.

But no matter how hard they campaign, they say the system put in place after the 1997 handover to China from British rule is rigged against them.

"The rules of the game are almost fatal for the democratic camp," said Frederick Fung of the Hong Kong Association for Democracy and People's Livelihood, a small democratic party.

Thirty of the seats in the assembly are elected by so-called functional constituencies, made up of mainly pro-Beijing members of professional bodies including wealthy businessmen.

Half are directly elected from geographical constituencies where anyone is free to nominate -- and where pro-Beijing parties generally fare poorly.

The remaining five seats in the new assembly -- expanded from 60 to 70 seats under changes agreed two years ago -- will be directly elected from members of district councils currently dominated by pro-Beijing parties.

Pro-democracy candidates also complain that on top of the structural disadvantages, they face funding challenges because potential donors do not want to jeopardise business prospects in China by backing the democratic camp.

But analysts say the democrats also have themselves to blame for their failure to pose a more coherent challenge to the pro-Beijing elite, due to petty divisions within their ranks over technical issues.