HONG KONG — Pro-China canvassers are pressing wary Hong Kong residents for signatures. The city’s business tycoons are declaring their faith in the Chinese government. Local officials, senior and junior alike, are stepping up to pledge their support, mimicking wooden displays of fealty that are a staple of Communist Party politics in the mainland.

The Chinese government has mounted an aggressive campaign to cast a more positive light on its treatment of Hong Kong, where residents have pushed back sharply against Beijing’s increasingly heavy hand. The new drive is intended to demonstrate a broad level of support among civil servants, business leaders and the city’s more than seven million residents for a new national security law that Beijing is forcing the former British colony to adopt.

“They are doing everything they can to drum up a welcoming vibe about this new law,” said Claudia Mo, a pro-democracy lawmaker. “It’s simply sickening. Who are you trying to fool?”

The campaign represents a brazen attempt by China’s leader, Xi Jinping, to drown out critics at a time when China is facing a global outcry over its plan for Hong Kong. With the United States threatening economic punishment in retaliation, Chinese officials are promoting the idea that they are responding to the will of the Hong Kong people and that their authoritarian policies enjoy broad public support.

The law has not yet been drafted, though China’s top legislative body on Thursday approved the plan to enact one, perhaps by September. The plan reflects Beijing’s frustration with pro-democracy protests that have roiled Hong Kong since last year. Critics worry that any law would undermine the territory’s liberties, including its tradition of free speech and an independent judiciary, allowing Beijing to stamp out dissent.

On Friday, China’s Ministry of Public Security, the national police and border control, promised in a statement on its website to apply “all of our efforts to direct and support the Hong Kong police to stop violence and restore order.” Hong Kong has its own police force, and the ministry does not currently have any legal enforcement authority in the territory.

Polling data on the new law is limited, but recent events suggest it will not be well received. Officials have avoided pushing such legislation since 2003 because it was seen as deeply unpopular. Pro-democracy candidates won 57 percent of the vote in district-level elections in November, trouncing their pro-Beijing rivals.

To counter that narrative, Mr. Xi, China’s most powerful leader in decades, is deploying the same political playbook in Hong Kong that he has used to consolidate his power in the mainland, using public displays of loyalty to project confidence at vulnerable moments.

Chinese officials use such shows of allegiance — known as biao tai, or expressing one’s position — to uphold Mr. Xi’s decisions to sideline political opponents and to tighten control of the media.

“They want this kind of well-orchestrated drama to present the picture that they have the people behind them, when clearly the majority of Hong Kong people are against the new law,” said Willy Lam, a political analyst at the Chinese University of Hong Kong. “The message to the opposition is: ‘We have already garnered the support of so many people, so it is futile to oppose it.’ ”

More than a dozen Hong Kong officials, including the leaders of the police, fire and immigration departments, have offered strikingly similar endorsements of a new law.

They have denounced the antigovernment protesters as rioters. They have warned about the threat posed by terrorism and argued that stricter laws are necessary for long-term prosperity.

The statements are a jarring display of conformity in a city known for impassioned debate, and they reflect Beijing’s growing influence in the territory, experts say.

“The civil service used to be more politically neutral,” said Mr. Lam, the analyst. “Hong Kong is increasingly following the Communist Party’s customs.”

Carrie Lam, Hong Kong’s chief executive, has helped lead the charge. She has said the law has drawn a “positive response” from citizens and that foreign investors are eager for a safe environment. On Thursday, she stood alongside residents of a pro-Beijing neighborhood and signed a petition in support.

Mr. Xi recently dispatched a top deputy to meet members of the city’s business elite who had traveled to Beijing for the annual meeting of China’s legislature. The deputy, Han Zheng, who oversees Hong Kong policy, praised them for their diligence and reminded them of their duties as party members to publicly support the law.

Then came the talking points. Growing unrest forced Beijing to push through legislation, Mr. Han said, according to a video of the meeting released by the Chinese government. Social stability was important for Hong Kong’s economy, he said.

Hong Kong’s business community once served as a buffer to Beijing’s hard-line policies. But the party has brought many business leaders to its side in recent years, turning to them for support during crucial moments of political instability.

Hong Kong’s tycoons and business elite control about one third of the seats of the Legislative Council, the city’s lawmaking body. Their support is rewarded by lucrative deals on the mainland.

“They fall into line when they need to because they hold the balance of power in the chief executive elections and in return their business is looked after on the mainland and here,” said David Webb, a longtime Hong Kong investor.

Beijing’s campaign has prompted even moderate members of the establishment to change their tone.

Michael Tien, a pro-Beijing lawmaker who had called for compromise during last year’s protests, said stricter laws were necessary. After attending legislative meetings over the last week in Beijing, he said he had become convinced that China intended to use the law to go after a “small majority of people in Hong Kong who are instigating conflict.”

“The radicals are coming back,” Mr. Tien said of the protests. “It has gone beyond my tolerance and patience.”

The party has also activated its network of supporters in Hong Kong.

A group affiliated with the pro-Beijing establishment has set up booths with red, white and blue banners to gather signatures in support of the law. The group, known as the United Front Supporting National Security Legislation, has collected more than 1.8 million signatures, according to Chinese state media.

The group’s advisers include Starry Lee and Regina Ip, two pro-Beijing politicians. During her time as Hong Kong’s top security official two decades ago, Ms. Ip tried and failed to pass a law against subversion and treason known as Article 23.

Ms. Ip said the petition drives were organized by “dyed-in-the-wool patriots.” She said that while she was an adviser, she had not been taking part in the street activities because of “scheduling conflicts.”

“In principle of course we support it but I haven’t seen the details,” Ms. Ip said of the security law. But, she added, “it needs to be consistent with common-law principles so that our judges and police can enforce it.”

At lunchtime on Thursday, several volunteers for the group held clipboards on a crowded walkway in Hong Kong’s bustling Causeway Bay neighborhood.

While the group’s website required people to provide names, the last four digits of their government identification numbers and their phone numbers, passers-by in Causeway Bay were asked to sign without providing any other personal information. Signatures ranged from full names and English first names to illegible scribbles.

Peggy Lau, 40, offered her signature. She said the protests have “made the environment really bad and unsettling.”

“Marches that express people’s demands are fine, but not violence,” said Ms. Lau, who works in finance. “It affects our livelihoods so much.”

In mainland China, the state-run news media has provided heavy coverage of statements of support from Hong Kong officials, business leaders and workers. China Central Television, the state broadcaster, said the petition drive showed that “all walks of life in Hong Kong fully support Hong Kong to defend the national security law.”

Ms. Mo, the lawmaker, said the campaign showed that the party viewed Hong Kong as a regular Chinese city and that it would demand the same ideological conformity that it imposes in the mainland.

“When I was young I was taught you do not get harmony if everyone sings the same note,” she said. “That pluralism, that diversity, is supposed to be good. Now there’s no such thing.”

Javier C. Hernández reported from Taipei, Taiwan, and Alexandra Stevenson from Hong Kong. Elaine Yu contributed reporting from Hong Kong. Cao Li and Albee Zhang contributed research.