People walking past advertising as they cross the Chinese border from the city of Shenzhen into Hong Kong, Sept. 6, 2017 .

Falling numbers of new residents in Hong Kong are now able to speak the city's lingua franca, Cantonese, amid warnings that a growing emphasis on Mandarin could threaten the city's indigenous culture.

Around 166,000 thousand "new Hong Kongers" were listed on the city's 2016 census, which indicates residents who were born across the internal immigration border in China, but who became resident in the city within the previous seven years, the city's census and statistics department said in a new analysis of the data.

While inward migration from China fell slightly compared with the previous census in 2006, mainland Chinese citizens settling in Hong Kong are now better educated than in the past, and fewer of them said they could speak Cantonese, one of the city's official Chinese languages.

Cantonese is the "usual spoken language" for more than 91 percent of the city's population in 2016, but was spoken by just under 70 percent of inward migrants from China, the report found.

"I have lived in Hong Kong for more than 20 years, and my feeling is that the status of Cantonese is changing in favor of Mandarin," resident Chen Yang told RFA. "When I had just moved to Hong Kong, Mandarin was looked down on as the language of a hick from the sticks, a closed society."

Now, as China flexes its muscles and deploys growing international "soft power," it's Beijing's money that talks, Chen says.

"It's economics that decides the status of a language," Chen said. "I don't think this has anything to do with politics."

Social activist Sze Lai-shan, who heads the Society for Community Organization, said many of those who indicated they couldn't speak Cantonese in the census data are the spouses of businessmen who initially settled in neighboring Guangzhou, then sent for their wives to join them from elsewhere in China.

"A lot of them come from other provinces in China," Sze said. "In the past, about 80 percent of new Hong Kongers hailed from Guangzhou [where Cantonese is also spoken.] Nowadays, only about 60 percent of them do."

The scenario is still far from that imagined in the independent Hong Kong movie 10 Years, which envisages a dystopian future dominated by the ruling Chinese Communist Party where Cantonese is outlawed in favor of Mandarin, mainland China's national language.

But it has still sparked fears among local commentators, who say the city's traditional freedoms and way of life are already increasingly vulnerable amid growing political influence from Beijing, and point to the rise of Mandarin within the city's education system.

Campaign group Societas Linguistica Hongkongensis reported earlier this year that more than 70 percent of the city's primary schools have classes that use Mandarin as a teaching medium.

Gradual shift since 1997

In a recent commentary broadcast on RFA's Cantonese Service, political commentator Lam Kei said the shift away from Cantonese in Hong Kong's education system has been gradually accelerating ever since the 1997 handover to Chinese rule.

While the city's government talked up "mother-tongue medium education," shortly after the handover, Lam said, the plan hadn't been popular, as it left fluent Cantonese speakers ill-equipped to pursue degrees in Hong Kong's English-medium colleges and universities.

"Hong Kong is discovering, just like Guangzhou and Shenzhen a few years ago, that it is the last bastion of Cantonese, and that [the language] is heading towards extinction," Lam wrote.

Instead of "mother-tongue education," there has been an increasing focus on Mandarin as a language of instruction from schools, which have been offered huge financial incentives to teach Mandarin by Hong Kong's own government.

"Politicization is inevitable, because the teaching materials and textbooks come from mainland China," Lam wrote. "They are taking the opportunity to turn Mandarin teaching into brainwashing sessions."

"This will create favorable conditions for the destruction of Hong Kong's Cantonese culture," Lam said.

He said the growing popularity of Mandarin in Hong Kong schools is no accident.

"The Chinese Communist Party is trying to fundamentally change the thinking of the younger generation in Hong Kong," Lam warned.

In 2010, thousands of people took to the streets of Guangzhou to protest government plans to reduce Cantonese-language broadcasting in the city ahead of the Asian Games

The movement to "protect Cantonese" had its roots in social media, participants said, quickly becoming a trending topic on microblogging services like Twitter and on the QQ chat network.

Activists said at the time that the protest was about respecting the rights of a linguistic minority to preserve their language and culture, as enshrined in the International Covenant on Civil and Political Rights.

Generally, television stations in China are required to use Mandarin, but Guangzhou TV was given special approval in the 1980s to broadcast in Cantonese to attract viewers from neighboring Hong Kong and Macau, which were still under British and Portuguese rule, respectively.

Reported by Fok Leung-kiu and Ma Lap-hak for RFA's Cantonese Service. Translated and edited by Luisetta Mudie.