HONG KONG — The head of a political party calling for Hong Kong’s independence from China said Tuesday that government efforts to ban his group were a sign of eroding freedoms in the city.
Andy Chan, the founder of the Hong Kong National Party, spoke at the Foreign Correspondents’ Club, an event that Chinese and Hong Kong government officials had condemned.
Calls for the club to cancel the event raised questions about the future of free speech in Hong Kong, a semiautonomous part of China where protections for civil liberties are far more robust than in the mainland.
Leung Chun-ying, who served as Hong Kong’s chief executive from 2012 to 2017, said the government, which owns the historic building the club rents in downtown Hong Kong, should not welcome a tenant that hosts a speaker who advocates separatism.
In response to Mr. Leung’s criticism, the club said last week that it planned to go ahead with the talk.
Dozens of protesters gathered near the club ahead of the event. Some opposed the talk, while other demonstrators came to support Mr. Chan and his call for Hong Kong’s independence from China.
“I am here protesting for our country,” said George Ng, a retiree and member of Voice of Loving Hong Kong, a pro-Beijing group.
Mr. Ng, who was carrying a large Chinese flag, said he objected to the club giving Mr. Chan “a platform for his anti-state propaganda.”
Mr. Chan said that he considered his call for Hong Kong independence to be a natural part of the effort to promote democracy in the city.
“If Hong Kong were to become truly democratic, Hong Kong’s sovereignty must rest with the people of Hong Kong,” he said. “And there is only one way to achieve this: independence.”
Mr. Chan attacked the influence of China’s central government over the city, saying it treated Hong Kong with an even heavier hand than the former colonial ruler, Britain.
“The nature of China is oppression,” he said. “At its heart, the empire that existed in the 18th century still stands today, despite all its technological advances. China is not a modern nation-state, much less a civil society.”
A Hong Kong government spokesman said Tuesday that it was “totally inappropriate and unacceptable for any organization to provide a public platform to espouse such views.”
A group of pro-establishment Hong Kong lawmakers also criticized the talk. And the Hong Kong office of the Chinese Ministry of Foreign Affairs denounced the club, saying that by “providing a stage to ‘promote Hong Kong independence,’” it had “seriously hurt the feelings of the Hong Kong people.”
The ministry said the talk was beyond what could be considered reasonable free speech, like inviting Nazis to speak in Germany or terrorists to speak in the United States. Mr. Chan, however, said he and his party were advocates for peaceful political change.
“We condemn violence, we do not support violence and we never have been for violence,” he said.
Calls for Hong Kong independence were largely unheard of in this city a decade ago, and they still lack widespread public support. But after the 2014 demonstrations known as the Umbrella Movement, when protesters occupied major roadways for 79 days in an unsuccessful push for more open democracy, some activists became more vocal in their calls for the city to formally separate from China.
Official criticism of such ideas only gave them more attention, and Mr. Leung has sometimes been mockingly called the “father of Hong Kong independence” for highlighting the movement.
Mr. Leung is now a vice chairman of the Chinese People’s Political Consultative Conference, an advisory body to the central government.
His vocal criticism of Hong Kong independence could ensure that Mr. Leung is seen as an ally by the central government, said Maya Wang, a senior researcher for Human Rights Watch.
That pattern is similar to other parts of China that have independence movements, like the western regions of Xinjiang and Tibet, she said.
“That unfortunately results in authorities hardening their approach to these regions,” she said. “Instead of addressing legitimate grievances in those places over freedom of expression, participation, equality and justice, you are creating a hostile, tough approach to a certain segment of the population.”
During a visit to Hong Kong last year, President Xi Jinping warned against challenging the “red line” of Beijing’s sovereignty over the city, his most direct admonition of Hong Kong independence advocates.
Last month, the Hong Kong authorities moved to ban Mr. Chan’s party under a colonial-era law that authorizes the prohibition of groups that endanger national security, public safety and public order.
The law, formally known as the Societies Ordinance, is typically used against organized crime groups, and the proposed ban of the Hong Kong National Party would be the first application against a political party since Britain returned the territory to China in 1997.
Mr. Chan has until Sept. 4 to respond to the government’s proposed ban.
The Chinese Ministry of Foreign Affairs complained to the Foreign Correspondents’ Club about plans for the talk, titled “Hong Kong Nationalism: A Politically Incorrect Guide to Hong Kong Under Chinese Rule.”
Then Mr. Leung added to the criticism, using increasingly harsh rhetoric. “Would the club invite speakers who promote racism, anti-Semitism or Nazism?” he wrote Saturday on his Facebook page.
Mr. Leung also suggested the government was giving the club a break on its rent and that the lease should be reopened for other bidders. But Carrie Lam, the chief executive, said the club paid a market rate.
The club currently pays more than $73,000 a month for its building, a former cold-storage warehouse for a dairy. The rent has roughly doubled from the rent of about $37,000 it paid in 2008.
Victor Mallet, the club’s first vice president and Asia news editor for The Financial Times, said the club considered the talk a “normal event,” and that it regularly hosted speakers representing a range of viewpoints it neither endorses nor opposes
“The fact that this lunch seems to have become far from normal and has generated such exceptional interest in Hong Kong and around the world I think tells us more about the political climate in Hong Kong and in Beijing than it does about the F.C.C.,” he said.