When Hong Kong goes to the polls on Sunday a new brand of politician pushing for a complete break from Beijing will be fighting for votes in a frustrated and divided city.

It is the most important election since the mass "Umbrella Movement" pro-democracy rallies of 2014, which failed to win political reform despite huge numbers and a global spotlight.

Since then, fears have grown that Beijing is tightening its grip in many areas of the semi-autonomous city -- from politics to education and media.

Some young activists now say there is only one choice: a declaration of independence from China.

Many residents still dismiss the idea as a pipe dream, but the independence movement has gathered momentum as authorities in Hong Kong and Beijing rail against it.

Government officials have slammed it as illegal and some of the most strident pro-independence campaigners have been banned from standing in Sunday's vote for members of the Legislative Council, the city's lawmaking body, known as Legco.

That only fuelled the fire, with thousands coming out in support of the five barred candidates at Hong Kong's first independence rally in early August and opinion polls suggesting as many as 17 percent of people favour splitting with China.

Some candidates advocating self-determination for Hong Kong have been allowed to stand although only one or two candidates have a chance of winning a seat in the 70-member assembly.

But even that would be a coup for a fledgling movement pushing for a notion that until recently was taboo.

Baggio Leung, 30, is one of three candidates from new party Youngspiration, campaigning for self-determination. Polls indicate he could take a seat.

"People from Beijing are trampling our values... we need to find a way out," he told AFP.

Leung says there is now little faith in the semi-autonomous "one country, two systems" model, under which the city has been governed since it was handed back to China by Britain in 1997 and which is supposed to protect its way of life for 50 years.

"As the Communist Party in China is not fulfilling its promise, Hong Kong independence seems to be the only right option," says Leung.

- 'No way back' -

Nathan Law, 23, a leader of the 2014 pro-democracy rallies, is standing for office with new political party Demosisto, also pushing for a self-determination vote.

Law says he does not want to see Hong Kong become just another Chinese city.

"Since the Umbrella Revolution there is no way back," Law told AFP. "I feel a responsibility to this place."

However, a swing towards young activists on Sunday could ultimately benefit Beijing as it might tip the finely balanced Legco in the establishment's favour.

Currently, pro-democracy lawmakers hold 27 of 70 seats, enabling them to block bills, which need to pass by two thirds.

If new activists and veteran democrats, whose popularity is waning, split votes, pro-Beijing candidates may pick up extra seats.

That could further undermine the legitimacy of Hong Kong's political framework in the eyes of young campaigners.

"The younger generations and supporters of democracy may feel that fighting within the Legco has reached a dead end," says Chung Kim-wah, professor of social sciences at the University of Hong Kong.

For their part, pro-Beijing politicians argue any split from China would be a disaster for Hong Kong.

"'One country, two systems' is what brought Hong Kong here today... the pro-establishment camp needs to ensure Hong Kong's prosperity and stability," says candidate Wong Kwok-hing, of the Federation of Trade Unions.

But some in the city, where low salaries and lack of adequate housing are serious concerns, just want to see an end to the political wrangling -- and a tangible improvement in their lives.

Logistics worker Dicky Tsang, 56, accused both sides of "empty talk".

"I don't mind their background -- as long as they can get things done," he said.

That view was echoed by 18-year-old student Pau Chun-wai.

"I don't care which party they are from," he told AFP. "As long as they bring improvements to communities."