Leaders of Hong Kong’s pro-democracy movement on Tuesday appealed directly to legislators in the United States to exert pressure on Beijing, warning that an erosion of the city’s special status would embolden China’s leaders around the world.

In an appearance likely to infuriate Beijing, the activists at the forefront of Hong Kong’s mass protests testified before a congressional commission in support of US legislation aimed at defending Hong Kong people’s civil rights.

“This is not a plea for so-called foreign interference. This is a plea for democracy,” singer and activist Denise Ho told a hearing of the Congressional-Executive Commission on China on Tuesday.

The panel of witnesses also urged members of the commission, which includes senators and members of the House of Representatives from both parties, to take action even if it might affect Hong Kong’s economy.

“Beijing should not have it both ways, reaping all the economic benefits of Hong Kong’s standing in the world while eradicating our sociopolitical identity,” said Joshua Wong, secretary general of Hong Kong’s Demosisto party and leader of the Umbrella Movement.

He also warned that Chinese President Xi Jinping may take harsher action ahead of celebrations on October 1 to mark the 70th anniversary of the People’s Republic of China.

“Sending in the tanks remains irrational, though not impossible,” Wong said.

Members of Congress at the hearing also pushed for a look at Hong Kong’s special trade status.

“The United States and other nations have options precisely because Beijing benefits from Hong Kong’s special status – a special status which has made Hong Kong an international financial centre built on the promises that China made to the world with regards to Hong Kong, which they seek to break,” said Senator Marco Rubio, the Republican cochairman of the commission.

The former British colony has been rocked by more than three months of sometimes violent clashes, with demonstrators angry over what they see as creeping interference by Beijing in Hong Kong’s affairs, despite a promise of autonomy.

PROTECT Hong Kong Act

Hong Kong returned to China in 1997 under a “one country, two systems” formula that guarantees the city’s residents freedoms not enjoyed on the mainland, including an independent legal system. China in 1997 promised to guarantee the freedoms for 50 years.

Medical workers display their palm with five fingers, signifying the five demands of protesters and chanted slogans as they stood in the foyer of the Prince of Wales Hospital in Hong Kong on Monday [Vincent Yu/AP]

The trigger for the unrest was an extradition bill, now withdrawn, that would have allowed people to be sent from Hong Kong to mainland China to stand trial.

Legislation was introduced in the US Senate and House earlier this year that would require an annual review of the special treatment Washington gives Hong Kong, including trade and business privileges.

The Hong Kong Human Rights and Democracy Act would also make officials in China and Hong Kong, who have undermined the city’s autonomy, vulnerable to sanctions.

Another bill introduced in the House last week with support from Republicans and Democrats, the PROTECT Hong Kong Act, would bar commercial exports of some crowd-control items to the Hong Kong police force.

The legislation has not come up for a vote, but the Senate Foreign Relations and House Foreign Affairs committees are both holding hearings this week expected to address relations with China on issues including Hong Kong.

President Donald Trump, who has been waging a tit-for-tat tariff war with China for more than a year, has suggested China should “humanely” settle the problem before a trade deal is reached.

Some industry groups worry that the legislation could threaten the delicate trade talks.

“Hopefully we will be able to pass some of this legislation to make it clear to the regime in Beijing that democracy is an important value,” said Senator Angus King, an independent who caucuses with Democrats.

Officials in Beijing as well as Hong Kong Chief Executive Carrie Lam have already accused the US of interference, and China has summoned Germany‘s ambassador after Demosisto party’s Wong visited the European power.