HONG KONG’S pro-democracy groups are planning a series of protests as the former British colony stages a huge party to mark 20 years of Chinese communist rule.

Fireworks, a gala variety show and Chinese military displays are among the official events coinciding with a visit by China’s president Xi Jinping, starting today.

State broadcaster China Central Television has been running daily news features extolling what it calls the inextricable ties that exist between China and Hong Kong in fields ranging from sports and the military to the arts.

Underneath the surface, however, tensions are simmering as Hong Kong people, especially the young, chafe at life under the tightening grip of China’s leaders.

“People are not celebrating but worrying about Hong Kong’s future and its current situation,” said Nathan Law, who at 23 was elected the city’s youngest MP last year and was a student leader of 2014’s massive “Umbrella Movement” pro-democracy demonstrations.

On Monday, members of the Demosisto political party, including young activist Joshua Wong, draped a giant flower statue bequeathed by Beijing in 1997 in black cloth, which they said symbolised “the hardline rule of the authoritarian regime”.

Other protests include a rally by a pro-independence group tomorrow evening and a pro-democracy march on Saturday, the latter an annual event that has drawn big crowds in the past.

Law said there was growing concern that Beijing was steadily eroding the “one country, two systems” principle put in place after it took control of the Asian financial hub.

Under that principle, Hong Kong largely runs its own affairs and enjoys civil liberties that are unseen on the mainland, but now, he said, “there are lots of people describing the current system as ‘one country, 1.5 systems’”.

He and others cited a list of incidents that stoke fears about China tightening control.

At the top is the case of five Hong Kong booksellers secretly detained on the mainland starting in late 2015 for selling gossipy titles about elite Chinese politics to readers on the mainland.

In a similar case, a Chinese-born tycoon with a Canadian passport went missing earlier this year from his hotel suite.

News reports indicated mainland Chinese security agents operating in Hong Kong abducted him – a breach of the city’s constitution.

Many other government plans have raised hackles, including stationing Chinese immigration officers in a high-speed rail terminus under construction; setting up a local branch of Beijing’s Palace Museum without public consultation; introducing so-called patriotic national education in schools that many parents fear is a cover for pro-communist brainwashing; and introducing anti-subversion national security legislation.

Another worry, said veteran pro-democracy MP Claudia Mo, was the flood of so-called “red capital” as mainland investors buy up property and expand businesses in Hong Kong, elbowing aside indigenous tycoons.

The wave of buying has been blamed for further inflating housing prices that make Hong Kong one of the world’s most unequal places.

“We’re supposed to be capitalists, fine. Except when it comes to public auctions of land, when all the big mainland concerns will always win,” Mo said.

Xi’s three-day visit includes an inspection of People’s Liberation Army troops based in the city and ends in the swearing-in of Hong Kong’s new leader Carrie Lam.

Police are stepping up security, with news reports indicating officers will crack down on political banners and images.

China’s Communist Party leaders are eager to tout the success of “one country, two systems”, envisaged as a way to entice back Taiwan, which Beijing sees as a renegade province.

The recent tensions have drawn “serious attention” from Beijing, which cannot afford to see pro-independence sentiment in Taiwan and Hong Kong at the same time, said Liu Shanying, political researcher at the Chinese Academy of Social Sciences.

“Therefore, it must be put under control,” whether by force or gentler methods, he said.

For many in Hong Kong, the fundamental problem is the legitimacy of the city’s Beijing-backed leaders.

Lam was chosen by a coterie of pro-Beijing elites over a far more popular rival in what pro-democracy activists slammed as a fake election. The system was at the root of the 2014 protests.