A senior Chinese politician who crushed a mainland democracy movement has been appointed to oversee the implementation of the controversial national security law in Hong Kong, reported ucanews.com.

On July 3 Zheng Yanxiong took charge of the office to implement the law that bans subversive and secessionist actions in the former British colony. Zheng is a former mayor and Communist Party secretary of Guangdong province, bordering Hong Kong.

Chan Lok-shun, an officer of the Justice and Peace Commission of Hong Kong Diocese, told ucanews.com July 7 that the latest appointment is a sequel to the selections of two other politicians who proved to be "tough" in handling situations.

"It shows China's determination to handle Hong Kong with an iron fist," said Chan.

Bypassing laws in Hong Kong, Zheng will report directly to the Chinese Communist Party. His office can handle cases as it sees fit. Suspects could be sent to face trial in mainland Chinese courts.

His powers include the authority to give advice, which under the Communist Party setup must be heeded without exception.

Zheng, 56, was made deputy director of the Guangdong provincial policy research office in 2002 and became deputy mayor of Shanwei in 2005. He was named mayor and became party secretary of Shanwei in September 2011.

In that same month, residents of Wukan fishing village accused officials of taking away their land in a series of underhand deals with property developers. As part of a negotiated deal, villagers were given the right to elect their own council -- hailed as a grassroots democratic exemption in communist China.

Five years later, in 2016, people took to the streets following their elected village chief's arrest. When the rebellion peaked, it was handed over to Zheng to quell. Police were ordered to seize control and mass arrests followed, putting an end to the "Wukan experiment."

Since the Wukan episode, Zheng has moved up through the ranks and gained a reputation for being a strongman.

Zheng's new role follows a pattern of appointments by Chinese President Xi Jinping in dealing with Hong Kong's pro-democracy movement, observers say.

In January, senior Communist Party member Luo Huining was appointed to head the Liaison Office of the Central People's Government in Hong Kong. His job, media reports say, involves enforcing the Communist Party's wishes in the territory.

In February, the party appointed Xia Baolong, known for leading cross removals in Zhejiang province, as the director of the Hong Kong and Macau Affairs Office that coordinates cooperation between the mainland and special administrative regions.

"The three of them are not only tough but they also were not involved with the affairs of Hong Kong in the past. This is an advantage" to Xi as these officials may "be able to implement the party's command accurately and firmly without any baggage of history," Chan said.

When Britain handed back Hong Kong to China in 1997, certain democratic rights were guaranteed for at least 50 years under the "one country, two systems" agreement.

The imposition of the security law practically brings Hong Kong under full Chinese administration and indirectly ends the agreement that allowed Hong Kong's semi-autonomous status.

Hong Kong chief executive Carrie Lam also has been given more power under the new security law. She has already handpicked six judges to hear cases under the new legislation.

On July 3, the day Zheng took charge, a man carrying a "Liberate Hong Kong" sign became the first person to be charged with inciting secession and terrorism under the new law.

Beijing implemented the law June 30 despite protests from Hong Kong residents and Western nations.

The Hong Kong government has confirmed that speech will also come under the purview of the security law, including slogans from the pro-democracy movement that has rocked the Asian financial hub for the past year.