The vote for Hong Kong's new leader kicks off this week, but most of its 3.8 million-strong electorate will have no say in choosing the winner, prompting calls for an overhaul of a system skewed towards Beijing.

It is the first leadership vote since mass pro-democracy protests in 2014 failed to win political reform and comes as fears grow that China is tightening its grip on semi-autonomous Hong Kong.

As the first round of voting begins, the four candidates are wooing the public -- dropping in to no-frills cafes to eat local dishes with ordinary folk. But to little avail.

The winner will be chosen by a committee of 1,200 representatives of special interest groups, weighted towards Beijing. According to a count by local media, only around a quarter are in the pro-democracy camp.

The representatives are selected by a pool of around 230,000 voters from sectors ranging from business to education, and include the city's 70 lawmakers.

Democracy campaigners and some residents say it is inevitable the winner will answer to Chinese authorities -- activists already vilify current leader Leung Chun-ying as a puppet of Beijing.

"The members of the electoral committee are only looking out for their own interests, how can they represent the Hong Kong people?" says engineer Stone Shek, 49.

Hong Kongers were offered the chance to vote for the next leader in a Beijing-backed reform package, which stipulated that candidates must first be vetted, triggering the huge 2014 "Umbrella Movement" rallies.

The proposal, dismissed by protesters as "fake democracy", was eventually voted down by lawmakers and the reform process has since been shelved.

Shek said rejecting the proposal was the right thing to do.

But others fear Chinese authorities will never compromise.

"They didn't heed the tens of thousands that came out to protest the Umbrella Movement," said IT worker Tony So, 42, who believes anyone over 18 should be able to vote for the leader.

- 'Lesser evil' -

Election committee members start nominating their favourite candidate in the first round of voting on Tuesday.

Each needs 150 votes by March 1 to participate in the final election by the same committee on March 26.

Tough former deputy leader Carrie Lam is considered Beijing's favourite, while ex-finance secretary John Tsang is the other main contender, seen as a more moderate voice and leading in public opinion polls.

They take on hardliner Regina Ip and former judge Woo Kwok-hing, who is considered most sympathetic to the democracy camp.

Veteran activist Leung Kwok-hung -- known as "Long Hair" -- has said he may enter the race, but as yet there is no clear candidate from the pro-democracy side.

Many democracy supporters thought there was little point fielding a candidate who would have no chance with the pro-Beijing committee, says activist and academic Chan Kin-man.

Instead, democratic committee members would likely back Tsang as the "lesser evil", he told AFP.

Activist Benny Tai, who founded the Occupy movement that helped galvanise the 2014 protests, compared the election to a "horse race" that residents can observe, but not influence.

"We need to work hard to maintain the movement and we will continue to strive for democracy," he told AFP.

Campaigners say they are playing the long game, hoping to build representation from the ground up -- citywide public elections in September saw former Umbrella Movement leaders become lawmakers.

But since then, two pro-independence legislators have been barred from taking up their seats after Beijing protests, while other pro-democracy figures are also facing disqualification.

Some residents say they have faith the election committee will choose the right leader.

"The people in the 'small circle' also want Hong Kong to prosper and develop," said finance analyst Polly Chen, 50.

But eventually, Chen added, Hong Kongers should decide.

"We have to start somewhere," she said of the road to reform.

"We may get it wrong, but we need to start."