Chinese officials tasked with the delicate issue of managing relations with Hong Kong are combining symbolic openness with a hard line as they make sure residents and local officials understand the central government’s will.

Hong Kong, a semi-autonomous region of China since former colonial ruler Britain handed it back nearly 21 years ago, has recently seen both sides of Beijing’s approach.

In a bid to show a softer side, China’s representative office in Hong Kong last weekend opened its doors to the public for the first time.

The function of the office — known officially in English as the Liaison Office of the Central People’s Government in the Hong Kong Special Administrative Region — has been seen as a “little mysterious,” said Wang Zhimin, the Chinese official who heads it.

“It’s not mysterious at all,” Wang said, according to an account of his remarks at the event posted on the office’s website.

A harder side was also on view last month when a visiting former Chinese legislative official said that advocating independence for Hong Kong did not fall within the territory’s free speech guarantees as it goes against the broader national constitution.

National sovereignty is an issue on which Beijing has long shown consistency, said Tim Summers, a lecturer in Chinese studies at the Chinese University of Hong Kong.

But it is one on which officials have felt challenged in recent years by some in Hong Kong, which helps explain why they are choosing to stress “this red line of sovereignty,” Summers told CNBC.

The gulf between the interests of a massive state governed by a single party intolerant of dissent and a small, increasingly polarized territory proud and protective of its legal and free-speech traditions make Beijing’s task difficult.

China is “trying to get people in Hong Kong to fall in line without appearing as overbearing,” said Steve Tsang, director of the London-based SOAS China Institute.

“The problem really is that the way they are doing it will still be seen by people in Hong Kong as actually quite overbearing,” Tsang said. “And there’s practically no way of avoiding that.”

As part of the deal brokered between China and Britain for Hong Kong’s return, the territory was guaranteed certain rights and freedoms enshrined in a charter known as the Basic Law, with the system said to be secure for 50 years.

The central government, however, has been widely seen as eroding that regime.

Events came to a head during civil unrest and street protests in 2014 sparked by demands for more democracy in Hong Kong. Those were ultimately quashed by local authorities, exposing fissures within the territory over relations with the central government.

“The problem is they have very few tools or capability to influence a lot of Hong Kong opinion,” Summers said.

“People certainly don’t think something just because someone from Beijing says that’s what they should think,” he said, stressing that opinions in Hong Kong have become increasingly polarized on how to deal with Beijing.

Tsang said that Chinese authorities, who make no distinction between self-determination and independence, should avoid overreacting to calls for more of a say that have arisen since the 2014 crackdown.

“The more Beijing tries to actually control Hong Kong more tightly, the stronger the reactions they will find from the local political activists,” he said. “And Beijing does not understand that or accept that.”