(NEW YORK) -- New York City firefighters and other city workers protested outside the mayor's residence Thursday, as a COVID-19 vaccination deadline quickly approaches.
Nearly all municipal employees, including police officers, sanitation workers and firefighters, have until 5 p.m. Friday to submit proof of receiving at least one dose of vaccine. Those who don't get vaccinated will be placed on unpaid leave, starting Monday, for at least 30 days, and their future employment will be resolved in negotiations with individual labor unions. Uniformed correction officers have until Dec. 1 to show proof of vaccination.
The city's firefighters' unions organized Thursday's anti-vaccine mandate rally, which filled the entire block in front of Gracie Mansion, home to Mayor Bill de Blasio. Municipal employees, including FDNY union members, and others gathered, some holding signs that said "My body my choice" and "Coercion is not consent."
Uniformed Firefighters Association of Greater New York President Andrew Ansbro previously told reporters that "a lot" of the union's members were "still struggling with making this decision." James McCarthy, president of the Uniformed Fire Officers Association, has also argued that the deadline, announced on Oct. 20, is "not enough time to make a retirement decision if you are going to retire from this job."
Ansbro has warned of a "catastrophic manpower shortage" if some 3,500 firefighters who are currently unvaccinated are unable to report to work. The FDNY said Wednesday that 65% of its members were vaccinated.
The mayor stood by his vaccine mandate Thursday, saying there are no plans to change the deadline.
"My job is to keep people safe, my employees, and 8.8 million people, and until we defeat COVID, people are not safe," de Blasio said during a press briefing. "If we don't stop COVID, New Yorkers will die. We must, must stop COVID and the way to do that is vaccination. And that must include our public employees."
On potential shortages in the city's fire, police and sanitation departments, de Blasio said that the agencies are "confident" about contingency plans, and that the city has anticipated that "a lot of the vaccinations would happen toward the end of the deadline."
Overall, 86% of the city's 300,000-plus workforce is vaccinated, de Blasio said. That includes school and hospital employees who faced earlier deadlines.
For outstanding city workers, that number drops to 76%, including 74% of police officers and 67% of sanitation workers, he said.
"We are very confident those numbers are going to go up a lot," de Blasio said.
Legal challenges to pause the city's vaccination mandate have so far been unsuccessful.
ABC News' Aaron Katersky contributed to this report.