Hong Kong (CNN) Hong Kong's annual memorial to the 1989 Tiananmen Square massacre is sparking a new kind of controversy, evident of a growing split within the city's democracy movement that may upend Hong Kong politics.

Attendance this year may be much lower than the tens of thousands of Hong Kongers that usually gather in the city's Victoria Park to commemorate the massacre in a grand display of defiance to Beijing from inside China's borders. Major pro-democracy organizations are abandoning the 26-year-old rally and rival events are being held around the city.

A pro-democracy group takes part in a rally outside the June 4 Museum on its opening day. A candlelight vigil commemorating the martyrs of the 1989 crackdown is held in the city's Victoria Park each year on June 4, attended by thousands.

A pro-democracy group takes part in a rally outside the June 4 Museum on its opening day. A candlelight vigil commemorating the martyrs of the 1989 crackdown is held in the city's Victoria Park each year on June 4, attended by thousands.

Today, Hong Kong is the only Chinese territory where commemoration of the June 4 crackdown is allowed. Here, pro-democracy legislator Lee Cheuk-yan (left) unwraps a replica of the Goddess of Democracy at Hong Kong's June 4 Museum that opened on April 24, 2014.

Hong Kong vigil – Today, Hong Kong is the only Chinese territory where commemoration of the June 4 crackdown is allowed. Here, pro-democracy legislator Lee Cheuk-yan (left) unwraps a replica of the Goddess of Democracy at Hong Kong's June 4 Museum that opened on April 24, 2014.

In the weeks following June 4, activists who were directly or indirectly involved in the pro-democracy demonstrations were arrested.

Punishment – In the weeks following June 4, activists who were directly or indirectly involved in the pro-democracy demonstrations were arrested.

June 4, 1989, students set fire to tanks. An official death toll has not been released but witnesses and human rights groups say hundreds were killed in the clash.

Students fight back – June 4, 1989, students set fire to tanks. An official death toll has not been released but witnesses and human rights groups say hundreds were killed in the clash.

June 4, 1989, journalists covering the crackdown were caught in the line of fire.

Caught in the middle – June 4, 1989, journalists covering the crackdown were caught in the line of fire.

On the night of June 3 and into the early hours of June 4, armed troops and tanks moved in on students and other civilians in the areas around Tiananmen Square, opening fire on the crowds.

Crackdown – On the night of June 3 and into the early hours of June 4, armed troops and tanks moved in on students and other civilians in the areas around Tiananmen Square, opening fire on the crowds.

Countdown to the crackdown: Unarmed troops first approached Tiananmen Square on June 2.

Troop movements – Countdown to the crackdown: Unarmed troops first approached Tiananmen Square on June 2.

This photo was taken on June 2, 1989, showing hundreds of thousands gathered around the Goddess of Democracy.

Mass protest – This photo was taken on June 2, 1989, showing hundreds of thousands gathered around the Goddess of Democracy.

May 30, 1989, students from the Central Academy of Fine Arts create a 10-meter-tall statue of the Goddess of Democracy to boost morale amongst student protestors in Tiananmen Square. Erected in just four days, the statue was unveiled in front of the Monument to the People's Heroes.

Monument to Heroes – May 30, 1989, students from the Central Academy of Fine Arts create a 10-meter-tall statue of the Goddess of Democracy to boost morale amongst student protestors in Tiananmen Square. Erected in just four days, the statue was unveiled in front of the Monument to the People's Heroes.

May 20, 1989, pro-democracy demonstrators raise their fists and flash the victory sign while stopping a military truck filled with soldiers on its way to Tiananmen Square.

Victory sign – May 20, 1989, pro-democracy demonstrators raise their fists and flash the victory sign while stopping a military truck filled with soldiers on its way to Tiananmen Square.

May 20, 1989, teachers from Beijing Normal University arrive at Tiananmen Square by the truckload to support their students after martial law was declared.

Student-teacher relations – May 20, 1989, teachers from Beijing Normal University arrive at Tiananmen Square by the truckload to support their students after martial law was declared.

May 19, 1989, the sixth day of hunger strikes. Communist Party General Secretary Zhao Ziyang arrives at Tiananmen Square to address the students. He begins his now-famous speech by saying: "Students, we came too late. We are sorry." The next day, Premiere Li Peng declares martial law in parts of Beijing.

Martial law – May 19, 1989, the sixth day of hunger strikes. Communist Party General Secretary Zhao Ziyang arrives at Tiananmen Square to address the students. He begins his now-famous speech by saying: "Students, we came too late. We are sorry." The next day, Premiere Li Peng declares martial law in parts of Beijing.

May 18, 1989, Chinese workers parade on motorbikes in support of student hunger strikers.

Biker backing – May 18, 1989, Chinese workers parade on motorbikes in support of student hunger strikers.

May 18, 1989 and Gorbachev has been in China for three days, witnessing street protests for each of those days. At the height of demonstrations, a million people were marching through Beijing.

Witness to discontent – May 18, 1989 and Gorbachev has been in China for three days, witnessing street protests for each of those days. At the height of demonstrations, a million people were marching through Beijing.

May 17, 1989: Five days in and the hunger strike begins to take its toll on students. Paramedics evacuate ailing protestors from the square.

Price of protest – May 17, 1989: Five days in and the hunger strike begins to take its toll on students. Paramedics evacuate ailing protestors from the square.

May 16, 1989, then Chinese President Deng Xiaoping (center) takes then Soviet President Mikhail Gorbachev and his wife Raisa by the hand at the Great Hall of the People. Gorbachev's visit coincided with the student hunger strikes, forcing the official reception to be moved from Tiananmen Square to the airport -- embarrassing for the Chinese leadership.

Gorbachev visits – May 16, 1989, then Chinese President Deng Xiaoping (center) takes then Soviet President Mikhail Gorbachev and his wife Raisa by the hand at the Great Hall of the People. Gorbachev's visit coincided with the student hunger strikes, forcing the official reception to be moved from Tiananmen Square to the airport -- embarrassing for the Chinese leadership.

Student hunger strikers camp out on top of buses parked at Tiananmen Square.

Tiananmen sit in – Student hunger strikers camp out on top of buses parked at Tiananmen Square.

May 13, 1989, student demonstrations at Tiananmen Square escalate into a hunger strike with thousands taking part and calling for democratic reforms.

Nil by mouth – May 13, 1989, student demonstrations at Tiananmen Square escalate into a hunger strike with thousands taking part and calling for democratic reforms.

Ousted General Secretary of the Communist Party, Hu Yaobang, dies at age 73 on April 15, 1989. The next day, thousands of students gather at Tiananmen Square to mourn him -- Hu had become a symbol of reform for the student movement. A week later thousands more marched to Tiananmen Square -- the start of an occupation that would end in a tragic showdown.

Timeline: Tiananmen Square crackdown – Ousted General Secretary of the Communist Party, Hu Yaobang, dies at age 73 on April 15, 1989. The next day, thousands of students gather at Tiananmen Square to mourn him -- Hu had become a symbol of reform for the student movement. A week later thousands more marched to Tiananmen Square -- the start of an occupation that would end in a tragic showdown.

Controversy

Since 1990, the Victoria Park vigil -- organized by the Alliance in Support of Patriotic Democratic Movements in China -- has called for the rehabilitation of the 1989 pro-democracy movement, the end of one-party dictatorship, and the building of a democratic China.

That last point has become a point of contention with many young people in the city, who object to equating Hong Kong with China and have called for the rally to focus more on local democratic development.

While there have been rumblings for a number of years, and two small alternative rallies last year, the controversy got a major boost last month when the Hong Kong Federation of Students (HKFS) -- the city's oldest and largest student organization -- announced it was leaving the Alliance and not taking part in the rally.

"(HKFS) have been on the forefront of the pro-democracy movement since 1989, and have always participated in the vigils for over 26 years" says Lee Cheuk-yan, Labour Party lawmaker and secretary of the Alliance.

"We feel sad this year that they're not going to take part."

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HKFS chairwoman Hillary Tjhan told the South China Morning Post that the Federation felt it should focus on the political development of Hong Kong, rather than building a democratic China.

The Federation did not respond to multiple requests for comment.

Speaking to RTHK radio, Chinese University of Hong Kong student union president Chow Shue-fung said the Victoria Park rally had become "rigid" and many in Hong Kong did not agree with how the Alliance "connects Chinese identity with building democracy in China and June 4."

"Vindication of the 1989 movement and building democracy in China are not moral responsibilities of Hong Kongers," he said.

Students at Shue Yan University took this criticism even further, issuing a statement saying the alliance has become "pimps and bawds in a brothel after they themselves were raped."

Why it matters

Mention of the Tiananmen Square massacre -- in which the People's Liberation Army bloodily cracked down on mostly student protesters, killing hundreds -- is still strictly censored in China.

Around the anniversary, online censors block mention of everything from 占占占占人 (symbolizing the famous "Tank Man" photo) to posts referencing "today" or "that day," according to China Digital Times

Relatives of those that died are regularly harassed and even imprisoned. In a statement released this week , the Tiananmen Mothers, which lobbies for justice for the victims of June 4th, said members are "eavesdropped and surveilled upon by the police; we are followed or even detained, and our computers searched and confiscated."

This makes the Hong Kong commemoration -- the biggest in the world and the only major one on Chinese soil (small rallies are also held in Macau every year) -- all the more important.

Photos: Hong Kong's Tiananmen museum to close Hong Kong's June 4th museum, which commemorates the Tiananmen Square massacre of 1989, is looking for a new, bigger location. Hide Caption 1 of 5 Photos: Hong Kong's Tiananmen museum to close Hong Kong Alliance, the group that runs the museum, say they have faced political pressure over the museum and its location. Hide Caption 2 of 5 Photos: Hong Kong's Tiananmen museum to close The museum was opened in 2014 and has seen more than 20,000 visitors pass through it since, according to the owners. Hide Caption 3 of 5 Photos: Hong Kong's Tiananmen museum to close Exhibits include original newspaper and magazine clippings about the massacre, and mementos of those killed donated by their families. Hide Caption 4 of 5 Photos: Hong Kong's Tiananmen museum to close The museum also sells a large collection of political books, many of which are banned in mainland China. Hide Caption 5 of 5

Localism

The controversy over the rally is related to the rise of so-called "localist" groups in Hong Kong , who advocate for greater autonomy for the city, with some pushing for full independence.

Part of that push is disconnecting Hong Kong issues from wider Chinese political development, and moving away from the "one country, two systems" consensus under which most traditional pro-democracy parties in the city have always operated.

That has put the rally in an awkward position, with some localists viewing attendance as implicitly accepting that Hong Kong is part of China and that the city's residents are Chinese.

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Some have rejected this view, including Nathan Law, former HKFS secretary-general and current chairman of Demosisto, a localist party that argues for Hong Kong self-determination

Law says he had his "political enlightenment" attending previous rallies, and it has "huge meaning for me."

"Even though I don't regard myself as ethnic Chinese, I still go to the memorial rally in Victoria Park," he told CNN.

"(The controversy) shows there's some division between the younger generation and the 1989 democracy movement generation," says Lee.

"We believe the fight for Hong Kong democracy and the fight for democracy in China are the same fight."

He said he understands the "identity issue" many younger Hong Kongers felt, but said it "should not be a barrier to working together to fight authoritarian rule."

Further split

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While the Victoria Park rally is ultimately just one event, there are concerns within the wider pro-democracy movement that the controversy is indicative of a bigger split that could effect the upcoming elections to the Legislative Council, Hong Kong's parliament.

"In a way this may be a prelude to the coming election, in terms of the differences between the two camps," says Lee.

While at least five new localist parties to emerge from the 2014 pro-democracy Umbrella Movement have announced plans to join forces in the upcoming elections, others, including Demosisto and pro-independence party Hong Kong Indigenous, have not.

"There's a danger that when the vote is split too much the (pro-Beijing) camp will win more seats with less votes," Lee says.

"I think everyone will suffer."