Other protesters gathered on a landscaped pedestrian bridge and a waterfront, singing hymns and joining in prayers led by representatives of religious groups. “We may be losing something precious,” Yip Po Lam, a Catholic priest, told the protesters. “But I hope we will not leave behind our values and our persistence.”

[Why are people protesting in Hong Kong? Catch up here.]

Mr. Leung, the president of the legislature, said Tuesday that he expected the extradition bill to go to a vote on June 20 after a total of more than 60 hours of debate, adding that “the case is pressing and has to be handled as soon as possible.” The measure is likely to pass, with pro-Beijing lawmakers holding 43 of 70 seats.

Opposition lawmakers had expected a vote around the end of the month, based on a regular schedule of meetings. Mr. Leung’s decision to add more sessions in the coming days in order to bring the date of the vote forward drew criticism.

Hong Kong’s stock market was down 1.5 percent around noon on Wednesday, as other markets in Asia saw little movement. While some small Hong Kong businesses had threatened to close down for the day to protest the extradition bill, big international companies with a presence in the city have been largely quiet, apparently for fear of offending the Chinese government.

The public furor over the bill is the most dramatic sign in years of rising fear and anger over the erosion of civil liberties in Hong Kong, a former British colony that was returned to Chinese rule in 1997.

Billy Li, a barrister and representative of the Progressive Lawyers Group, said he was angered by the decision to accelerate the vote after what he described as a record-breaking demonstration on Sunday. Organizers said more than a million people participated.

“The Legislative Council, as a body that regulates the government, not only failed to respond to the dissenting voices of the people but rather accelerated the situation,” Mr. Li said. “It is not willing to allow the people to understand the case but is hastily forcing the public to accept it.”