HONG KONG — After a campaign marred by scandal and alleged intimidation, the people of Hong Kong vote Sunday in legislative elections that could give pro-democracy figures more clout than they have held since China reclaimed Hong Kong in July 1997.

Ordinary citizens were expected to turn out in heavy numbers and hand most of their support to opposition politicians branded as troublemakers or even "traitors" by Beijing, but the pro-democracy camp was expected to fall short of a majority under an election system critics say is rigged.

Analysts predicted the opposition might claim 25-28 of the Legislative Council's 60 seats, compared with 22 now, which could further weaken the unpopular government of Chief Executive Tung Chee-hwa by making it harder for Tung to get his bills passed.

Beijing's authoritarian leadership has been clearly worried about the outcome of Hong Kong's greatest exercise of democracy since the handover. Critics charge that China, or its local allies, have mounted an orchestrated campaign to hold back the opposition as much as possible.

Hong Kong authorities have rejected such charges, and election officials promised free and fair elections. Responding to worries that some people have been told to back pro-Beijing candidates and prove it by photographing their ballots with mobile phone telephones, officials said such devices will be banned.

The politicians made final appeals to the voters Saturday, seeking to rally supporters amid last-minute jockeying in some key, tight races.

Ordinary voters will directly pick 30 of Hong Kong's lawmakers, but the other 30 are chosen by a relatively small group of special interest voters, like business leaders, doctors and accountants, who are expected to back pro-Beijing candidates.

Eleven of those seats already were filled before balloting even began, because candidates had no competition.

Critics say the system is unfair, giving 3.2 million registered voters the right to choose half of the seats while the other half are picked by less than 200,000 people, with some special interest races including secretive corporate voting.

Pro-Beijing politicians were campaigning hard Saturday on Hong Kong Island against the territory's best-known opposition figure, Democratic Party lawmaker Martin Lee, in an apparently close race.

"It's a very tight race — I'm doing my best," Lee said.

The chairman of the pro-Beijing Democratic Alliance for the Betterment of Hong Kong, Ma Lik, was stumping for votes after returning just two days earlier from mainland China, where he has received treatment for colon cancer.

Lee brought in help from a popular former radio host, Albert Cheng, who is expected to win a seat of his own in another district. Cheng is one of three radio hosts who went off the air in May, allegedly after receiving threats over their pro-democracy stances in one of the biggest controversies surrounding the contests.

The Democrats were hurt by money and sex scandals embroiling two candidates, one of whom was locked up in mainland China for allegedly consorting with a prostitute. The candidate, Alex Ho Wai-to, remained both in detention and on the ballot and was given little chance of victory.

Another close contest could lead to victory by an unlikely candidate — "Longhair" Leung Kwok-hung, a veteran anti-establishment activist known for fiery protest antics who has vowed to wear his trademark Che Guevara T-shirt into the legislature, although that would violate a dress code.

The political atmosphere in Hong Kong has been highly charged since 500,000 people stunned Beijing and Hong Kong leaders by turning out on July 1, 2003, to march against an anti-subversion bill viewed as a threat to freedoms. Tung had to withdraw it, but his political allies have been hurt by association.

Many Hong Kongers have been clamoring for the right to directly pick their leader in 2007 and all lawmakers in 2008, but Beijing stirred a public outrage by ruling it out in April — a decision expected to create a backlash against China's allies in the election.

Critics charged Beijing had violated its agreement to leave Hong Kong with a great deal of local autonomy after the handover.