Stores are shut down on Sunday after black-clad protesters illegally took to the streets in Central Hong Kong and blocked the roads. Photo: Chen Qingqing/GT

Rioters who threaten to paralyze Hong Kong's economy to force the government accept their demands are extremely irresponsible, said the president of Hong Kong's largest labor union.

The "freedom" rioters have been pursuing has actually sacrificed other people's freedom and rights, Stanley Ng Chau-pei, President of the Hong Kong Federation of Trade Unions (HKFTU), told the Global Times. 

The months-long citywide protests have hit Hong Kong's economy hard, as the government last week lowered its 2019 GDP growth forecast to between 0 and 1 percent, down from the original 2 to 3 percent. 

Ng said that commercial sectors including catering, services and retail have been greatly impacted by the protests. An optician's shop that Ng recently visited has seen their revenue drop by 60 percent. 

Ng predicted that these sectors are expected to witness heavier blows in the upcoming months. 

HKFTU, with 410,000 members from a wide spectrum of sectors covering transport, tourism, catering and retail industries, and manufacturing and government organizations, is the largest labor organization in Hong Kong. 

Ng's interview took place after the HKFTU Workers' Club building was vandalized by a group of black-clad protesters on August 17. The building was covered in profanities, painted using black spray paint.  

"It's a serious insult to the HKFTU and the labor group, we will never forget what they've done," Ng said. "They were heavily masked and opened umbrellas to cover themselves while painting the wall, which means their violence is premeditated and they were deliberately violating the law," he said. 

Ng said that those protesters have seriously challenged rule of law, and the trade union has demanded that the police bring those rioters to justice. 

Hong Kong media, which have been called "black terror," have been fanning the flames and taking side with the protesters, according to Ng. 

He said that the HKFTU has organized several gatherings in the past weeks to unite residents' righteous appeals so that more people can bravely say no to violence.