A Cantonese opera singer checks her make-up before a performance in Hong Kong. Commentators are warning that the growing influence of the Mandarin language in the city is threatening Cantonese culture. (Photo by Anthony Wallace/AFP)

Fewer new residents in Hong Kong can now speak the city's lingua franca — Cantonese — amid warnings a growing move toward Mandarin could threaten the city's indigenous culture.

Around 166,000 "new Hong Kongers" were listed in the city's 2016 census, which indicates residents born across the internal immigration border in China, but who took up residence in the city within the previous seven years, according to the city's Census and Statistics Department.

Of the Chinese citizens settling in Hong Kong in that time fewer of them said they could speak Cantonese, one of the city's official Chinese languages.

Cantonese was 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 migrants from China, the department said.

"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 Radio free Asia.

"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."

It has sparked fears among local commentators, who say the city's traditional freedoms and way of life are under threat amid growing political influence from Beijing.

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.

"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.

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